3EBIO: Joyas & Noel | Bohol by REANNA ROSARY NOEL https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm In the pursuit of knowledge do we grow like plants! en-us 2021-05-23 12:27:32 UTC 2025-01-22 14:40:59 UTC hello@padlet.com https://padlet.net/icons/png/1f331.png Stages of Embryonic Development reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552770797 The growth of plants start with the formation of a plant begins with the zygote after fertilization.

Image Source(s):
Plant Embryogenesis | University of Nairobi]]> 2021-05-24 05:52:14 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552770797 Apical-Basal Polarity reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552772235 First off, let's review the apical and basal ends of a plant

The cytoplasmic apical end is what gives rise to majority of the plant embryo. This end is what give rise to the octant and globular embryos due to the 2 longitudinal divisions and several transverse divisions. The WOX genes leads to apical polarity in cells but also has a role in the basal polarity of plants. Additionally, these WOX genes is able to activate PIN-1 genes which help establish the auxin polar transport, which will be discussed a bit more later on, but it also leads to apical fate.

The basal end, on the other hand, has a large central vacuole. This end also divides transversely to produce the suspensor with the upper most area producing the hypophysis. One of the genes that help initiate the establishment of the basal axis is the SSP mRNA from the male gametophyte. This will eventually lead to the activation of GRD (GROUNDED) gene that promotes elongation and asymmetric division

One of the main hormones that control the growth of the basal end is Auxin. This hormone is also observed to play an important role in the establishment of the apical basal patterning in plants during embryogenesis. The concentration gradient of auxin throughout the seed. Inhibition of the polar auxin transport (through 1-N-naphtylphtalamic acid) would severely affect the apical-basal patterning of the seed, specifically at the gynoecium of flowers.

Cytokinin, another very important hormone in the development of plants, inducing the shoots to elongate while also contributing to the apical polarization.

Source(s):

Abnormalities in somatic embryogenesis caused by 2,4-D: an overview | Springer Link

The RWP-RK Factor GROUNDED Promotes Embryonic Polarity by Facilitating YODA MAP Kinase Signaling | Science Direct

Cytokinin treatments affect the apical-basal patterning of the Arabidopsis gynoecium and resemble the effects of polar auxin transport inhibition | Frontiers in Plant Science

]]> 2021-05-24 05:52:51 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552772235 Seed Banks: Noah's Ark of Flora joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552774178 Seed Banks are repositories for the preservation of seeds of any plant from any point in the world. Kept in conditions that prevent germination or death, these banks allow almost perfect preservation of seed samples for future conservation, genomic editing, and so on! These seed banks are key for preserving the Flora of Earth, especially with the current threats they are facing.

Global Seed Banks are surfacing at different points of the world! The Svalbard Seed Vault in Norway houses seeds from Russia, Ukraine, Canada, and even North Korea! Capable of holding 2.5bn seeds, this vault is even found on the side of a mountain, in permafrost conditions. The Millennium Seed Bank Partnership (MSBP) at Wakehurst Place in England houses over 10% of the world's plant biodiversity! From Southeast Asia, to Central Asia, and seeds of various morphologies, the MSBP houses specimens from and with all of these.

With various threats looming about and threatening our flora, seed banks serve as a backup system. It is clearly vital to establish more and more of these repositories throughout the world.

Image Source(s):

Beyond the Gardens: Millennium Seed Bank Partnership | YouTube

]]> 2021-05-24 05:53:41 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552774178 Seed Dormancy reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552774730 The lack of germination in seeds despite being exposed to the proper conditions for growth is called seed dormancy. Often times, this is dependent on the permeability of the seed coat or the availability and activity of enzymes within the seed to start germination. To combat this, some plants have special requirements before they are able to break out of their dormancy.

Image Source(s):
Reasons or Causes of the Seed Dormancy | Byju's]]> 2021-05-24 05:53:55 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552774730 Seed Germination reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552777754 Germination takes place after seeds break dormancy via certain stimuli. We can split germination into three (3) phases, based on their rates of water uptake.

Image Source(s):
Sowing Seeds Indoors | GreenMyLife]]> 2021-05-24 05:55:15 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552777754 The Beauty of Bohol Flora reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552798353 Bohol is home not only to the famous Chocolate Hills and the adorable tarsier, but also to a variety of endemic flora! If we were given an opportunity to donate to a seed bank, for sure, these are our go-to species!

Let's explore together through this section! Let's Go, Boholano!

Image Source(s):

Chews Your Destiny | Cheezburger

]]> 2021-05-24 06:03:37 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552798353 Philippine Seed Banks: Dream or Reality? joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552923075 In the Philippines, there have been active efforts to establish seed banks throughout various localities and institutions.

Community Seed Banks (CSB) were established (together with UN-FAO) to support and empower small-scale farmers. The results are sound: these allowed farmers in Bohol to mitigate the effects of drought on their crop production and allowed enrichment of Dinorado in North Cotabato.

In the Cordillera Region, CSBs are also widespread. Traditional home CSBs through the su-ulan system is prevalent, which involves keeping the seeds constantly dry. A recent project of the PINE-TREE Group, together with the United Nations Global Environmental Facility (UNDP-GEF), has established three (3) seed banks for preservation of certain species.

On the international scale, the University of the Philippines-Los Banos holds a seed bank known as the National Plant Genetics Resources Laboratory (NPGRL). This repository was greatly damaged in 2006, due to Bagyong Milenyo, but has since slowly recovered. The International Rice Research Institute (IRRI), also in Los Banos, is a seed bank that currently holds over 127,000 samples. In fact, over 95% of their samples have duplicates in Svalbard!

With the Philippines being an agricultural country, it is reassuring to know that our country currently houses Seed Banks. Through these, we will be able to protect both our biodiversity and agriculture.

Image Source(s):
Vitamin E: From Preserving Beauty to Conserving Biodiversity | IRRI]]> 2021-05-24 07:07:56 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1552923075 Saving the World? Save the Plants, First! joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553049260 Nature doesn't need people. People need nature.
- Harrison Ford

Image Source(s):
Introducing CFS's Global Seed Network! | Center for Food Safety

]]> 2021-05-24 08:19:11 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553049260 Endemic Plant #1 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553203961 Ipomoea boholensis

A species of flora found only in Bohol, this flowering plant was originally described as Argyreia boholensis! Online, there are only eight (8) records of this specimen being available in international herbarium. Preserving this Bohol endemic species is, therefore, very important!

Image Source(s):
Ipomoea boholensis | PhytoImages]]> 2021-05-24 10:06:45 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553203961 Endemic Plant #2 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553232581 Blumea stenophylla

Another plant found only in Bohol, B. stenophylla only has four (4) occurrence sightings on online repositories! Being an endemic plant, we must ensure the survival of these species as they are not found anywhere else.

Image Source(s):
Blumea stenophylla Merr. | Plants of the World]]> 2021-05-24 10:28:37 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553232581 Take Note! joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553257347 The following plant species are no longer endemic to Bohol Island alone, but are distributed throughout the Philippines. Nonetheless, they are found on the island, and remain as important as ever to Bohol's Biodiversity!]]> 2021-05-24 10:47:51 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553257347 Endemic Plant #3 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553259074 Dendrocalamus sp.

Known natively as "kawayan," this genera of bamboo is seen around the municipalities of Bilar and Loboc. With kawayan being used in so many tools and instruments in our country, saving this in a seed bank is like saving our culture!

Image Source(s):
Dendrocalamus giganteus (Giant Bamboo) | Gardenia]]> 2021-05-24 10:49:09 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553259074 Endemic Plant #4 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553266254 Hoya albida

A plant distributed throughout the Philippines, this plant is described to also occur in the Rajah Sikatuna Protected Landscape (RSPL) by Aureo and his colleagues (2020). Having a backup of the species in a seed bank may be beneficial. This is in the worst case scenario that they start to decline: seeds with the same original gene pool from the protected area may be sent back from the bank for repopulation!

Image Source(s):
New Hoya | Rare Hoyas]]> 2021-05-24 10:54:36 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553266254 Endemic Plant #5 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553288579 Hoya aurigueana

Similar to H. albida, H. aurigueana is found throughout the Philippines, but described to occur in RSPL as well. Notably, in their study, H. aurigueana only had 2 occurrences out of the 1704 in the study, and a density of 0.02. Saving the species found in the landscape via seed banks is all the more highlighted!

Source Image(s):
Hoya aurigueana | PhytoImages]]> 2021-05-24 11:12:27 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553288579 Endemic Plant #6 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553303062 Asplenium apoense

First described in 1905, the fern A. apoense is known locally as "lukdo." Described to occur in RSPL as well, saving samples of the native lukdo also saves a portion of the native culture of Bohol!

Image Source(s):
Asplenium apoense | PhytoImages]]> 2021-05-24 11:23:34 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553303062 Endemic Plant #7 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553320771 Dendrocnide rigidifolia

Another plant described in RSPL and throughout Luzon, D. rigidifolia is sparsely mentioned in literature. Highlighting, researching, describing, and saving seed samples of lesser known species adds to the ever-growing literature for botany and global seed conservation efforts in seed banks!

Image Source(s):
Filibot.web | Flickr]]> 2021-05-24 11:35:28 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553320771 Endemic Plant #8 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553344957 Hopea philippinensis

A plant native to the Philippines, this species of tropical lowland rainforest tree is classified as endangered by the IUCN. Preferably, we must protect the species by protecting their native habitat (such as in RSPL, where they are found as well), but for assurance, saving seeds of this plant in the seed bank may also be performed. Saving samples of endangered species is always preferable as they can aid in future propagation and conservation efforts.

Image Source(s):
Hopea philippinensis | PhytoImages]]> 2021-05-24 11:50:22 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553344957 Endemic Plant #9 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553356269 Shorea astylosa

Another plant described as endangered by the IUCN, this dipterocarp is widely distributed in the Philippines, and is found in RSPL as well. Similar to H. philippinensis, saving samples of an endangered species is always welcome in seed banks! This is to ensure that the species will never be truly extinct.

Image Source(s):
Shorea astylosa Foxw. | Plants of the World]]> 2021-05-24 11:56:46 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553356269 Endemic Plant #10 joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553376262 Calamus merrillii

The famous plant known as "rattan," C. merrillii is widely used in various industries such as house-making, furniture, and even baskets! Found all over the Philippines (such as Laguna and RSPL), having samples of this species of iconic industrial plant is a must-have for seed banks!

Image Source(s):
Calamus merrillii | Plants and Cycads Society of Australia]]> 2021-05-24 12:07:01 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553376262 Monocot or Dicot, which one? reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553376767 There are may tell tale signs we can use to distinguish monocot plants from eu/dicot plants. As mature plants, the root systems, leaf venation and flower petal numbers are the few external characteristics we can use. However, we are still able to distinguish one from the other even when they are just seeds. This is because one of the biggest differences is that monocots only produce one cotyledon during embryogenesis. Eu/dicots, on the other hand, produce two cotyledons at the end of their embryogenesis. This is important because this completely changes the internal morphology of the seed. As mentioned earlier, eu/dicots are able to produce a heart-shaped stage with their cotyledons while monocots are not able to.

Image Source(s):
Monocot vs Dicot Plants | RsScience]]> 2021-05-24 12:07:17 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1553376767 Single Cell reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556844145 The single cell zygote undergoes asymmetric cell division, creating a polarity within the cell. This polarity is made up of apical/terminal cells which are small in size and the larger basal cells.

The apical cell is where majority of the plant embryo develops.

The basal cell becomes the suspensor cell as it continues to divide transversely. This continues to divide into a longitudinal file of cells resembling a petiole as the zygote grows into a 2-cell embryo.
This line of cells serves as an anchor for the embryo to the endosperm. It also acts as a nutrient conduit for the embryo during its development and contributes to the rise of roots though the hypophysis (distal end of suspensor).

Reference(s):
Plant Embryogenesis: Zygote to Seed | JSTOR
Image Source(s):
Plant Embryogenesis | University of Nairobi]]> 2021-05-25 08:24:43 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556844145 Continuous cell development reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556877184 The zygote continues to develop with the apical cell dividing into two longitudinally to form the two celled pro-embryo. Both cells divide the same way once again, forming the four celled pro-embryo or 4-celled filament. Continued division, this time transversely along the O' line, of the 4 cells gives rise to the octant form. The aforementioned O' line serves as the boundary between the two domains of the embryo

References(s):

Building a plant: cell fate specification in the early Arabidopsis embryo | Development

]]> 2021-05-25 08:40:22 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556877184 Globular Stage reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556913061 During this stage, cells start to divide periclinal to form the protoderm. This structure is the first histologically distinct tissue that the seed develops. Additionally, the three tissue systems can now be recognized based on the division patters. These are the dermal (outermost cells; epidermis & periderm), ground (innermost cells; parenchyma), and vascular (xylem & phloem) tissue systems.

As the name suggests, this stage is globular in shape, having a radial patterning. This will be further discussed in the next column.

Reference(s):

Building a plant: cell fate specification in the early Arabidopsis embryo | Development

]]> 2021-05-25 08:56:56 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556913061 Heart Stage reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556960450 Cotyledons start to arise from the globular stage and become more heart-shaped in appearance in dicots. Monocots are a different story as they only develop one cotyledon, thus, this heart stage does not appear in their development, but they still develop a cotyledon.

For this portion, we will be focusing on dicot seeds, showing the development of the heart stage.

During the early heart stage, the differentiation of most major tissue systems have already started. The process begins with two groups of cells dividing periclinal. This creates a bulge which will eventually emerge as the cotyledon lobes. A delineation of the two (2) main embryonic organ systems, cotyledons & shoot axis, also occurs. Organization also begins to form the root apical meristem (RAM) with contribution from the hypophysis and apical cell derivatives. At this stage, the hypophysis becomes integrated with the embryo and the procambium initials can also be distinguished at this point.

At this stage, the patterning shifts from a radial to axial pattering. This, as well, will be further discussed in the next column.

The continual cell division, growth, and differentiation develops the embryo to the torpedo stage.

Reference(s):

Building a plant: cell fate specification in the early Arabidopsis embryo | Development

Developmental Biology. 6th edition. | NCBI

]]> 2021-05-25 09:23:09 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1556960450 Torpedo Stage reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1557879680 The first thing to note at this stage is the degeneration of the suspensor and the establishment of the shoot apical meristem (SAM) and the RAM. These two are what allows the seed to germinate, developing adult structures once the right conditions are met.

This structure is what we often see within the seeds that are ready to be cultivated.

Should the cotyledons continue to grow, it will reach the walking stick stage or simply, the mature seed, where embryogenesis is arrested. This now leads to the desiccation of the mature seed, remaining dormant until germination conditions are met.

Reference(s):
Developmental Biology. 6th edition. | NCBI

Image Source(s):
Plant Embryogenesis | University of Nairobi]]> 2021-05-25 14:44:11 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1557879680 Radial Axis Establishment reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1557987572 This pattern starts to develop at the octant embryo where the two orientations are the periclinal (radial) and the clinal (circumferential).

There are five steps that leads to the formation of tissue layers forming the radial patterning of a plant. It begins with the delineation of the protoderm which would eventually lead to the formation of vascular tissues. These tissues successively form from the periphery going towards the center of the stem/root. This is how plants are able to keep their stems and roots in a cylindrical shape.

One of the genes identified to have at least some contribute to the establishment of this radial pattern is the knolle (kn) gene in embryos. In studies done where this gene was mutated, the plants lack their epidermis as it does not separate periclinal to the inner cell mass during the pre-embryo state. Thus, it is speculated that radial patterning is already initiated in the early embryo, despite the most identifiable stage for this pattern is the globular or 32-celled stage.

References(s):
Plant Physiology and Development Sixth edition | Sinauer Associates, Inc.
Axis Formation in Plant Embryogenesis: Cues and Clues | Cell Press]]> 2021-05-25 15:08:33 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1557987572 Gravitropism joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560867797 One of the important tropism responses for plants is Gravitropism! It is through sensing gravity that plants are able to tell its roots to grow downwards. To do this, the root caps of plants contain something called statoliths! Think of them as marbles with a smaller steel ball inside. That steel ball would always go downwards to gravity! Similarly, these statoliths tell the plant which way is 'down.' Once they know this, they are able to polarize the plant hormone auxin to the roots and promote root development!

Reference(s):
Gravity Signaling in Flowering Plant Roots | MDPI

Image Source(s):
What are statoliths? | Quora]]> 2021-05-26 10:08:37 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560867797 Phase 1: Imbibation joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560912856 Rapid uptake of water by the seed occurs. This is caused by a difference in water potential between the seed and its immediate environment! Since the water potential of the seed is lower, it will rapidly seep in. However, once the water potentials become equal, imbibition ceases. Additionally, the glycolytic and oxidative pentose phosphate pathways are reactivated.

Reference(s):

Metabolic Processes During Seed Germination (Ali & Elozeiri, 2017) | InTechOpen

Seed Germination and Dormancy (Bewly, 1997) | NCBI

Image Source(s):
How Does Water Affect Plant Growth? | Gardening Know How

]]> 2021-05-26 10:39:27 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560912856 Phase 2: Metabolic Activation joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560941349 Once water uptake ceases, the second phase occurs. Various metabolic pathways in the seed activate, preparing for the eventual mobilization of food reserves. Old mRNAs are broken down, and the rate of transcription and translation of new mRNAs for growth are enhanced. Respiration and synthesis of macromolecules are activated once again, while hydrolysis starts to begin. Most importantly, at this point, the radicle of the seed begins to emerge as the cells within begin to expand.

Reference(s):

Metabolic Processes During Seed Germination (Ali & Elozeiri, 2017) | InTechOpen

Image Source(s):
MIsprouts Learn: What’s Inside A Seed? | MIGarderner

]]> 2021-05-26 10:58:38 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560941349 Phase 3: Reserve Mobilization joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560998825 In the final phase, the seed begins to mobilize it's food reserves stored within the storage tissues. Additionally, it begins to intake water once again, preparing for growth. Food reserves are primarily mobilized via the plant hormone Gibberellic Acids (GAs). At this phase, the seed begins to synthesize and send GAs to the plant endosperm's aleurone layer. The cells in this layer are then promoted to produce α-amylase and send them back into the endosperm. This enzyme finally breaks down the reserve starch of the embryo, allowing the scutellum to absorb the nutrients and thereby promoting growth.

Reference(s):

Metabolic Processes During Seed Germination (Ali & Elozeiri, 2017) | InTechOpen

Image Source(s):
Aleurone Layer | Toppr

]]> 2021-05-26 11:35:44 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1560998825 GA-GID1-DELLA Pathway joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561030168 When germinating seeds are finally growing, they must be able to break down their reserve starch within the cells. They do this by secreting GAs to the aleurone cells, which are the ones responsible for promoting α-amylase production! This involves a complex pathway that ultimately allows intake of nutrients by the embryo scutellum.

Once GAs enter the aleurone cell, they move to the nucleus and bind to the GID1 receptor. This receptor undergoes a conformational change, allowing the DELLA protein to bind further to it. This DELLA protein blocks the promoter of the GA-MYB gene, which is used later on. The DELLA protein bound to GID1 is eventually polyubiquitinated and broken down by the 26s proteasome. Returning, as DELLA is now removed, the promoter of the GA-MYB gene is now capable of undergoing transcription. GA-MYB is translated in the cytosol into a GA-MYB transcription factor, and enters the nucleus once again. Binding onto promoter genes of α-amylase and other hydrolases, GA-MYB effectively activates the transcription of the mRNA of these enzymes. Finally, the mRNA is sent to the rough endoplasmic reticulum (ER), where α-amylase and other hydrolases are synthesized, packed into Golgi bodies, and ready to undergo exocytosis. The last process requires GAs again, as they are the 'exit pass' required to stimulate secretory calcium-calmodulin dependent pathway for α-amylase to exit the aleurone cell.

Through this complex pathway, GAs were able to promote α-amylase production, which are now capable of breaking down the plant embryo's food!

Reference(s):
The α-Amylase Induction in Endosperm during Rice Seed Germination Is Caused by Gibberellin Synthesized in Epithelium (Kaneko et al., 2002) | NCBI

Gibberellin-regulated expression of a myb gene in barley aleurone cells: evidence for Myb transactivation of a high-pI alpha-amylase gene promoter (Gubler et al., 1995) | NCBI

Image Source(s):
Mobilization of Stored Reserves | SpringerLink]]> 2021-05-26 11:52:23 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561030168 GNOM Gene reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561116651 It was found that GNOM genes regulate the formation of vesicles within the membrane as it encodes an ARF guanine-nucleotide exchange factor (ARF-GEF). Relating this to another gene mentioned earlier, PIN-1, GNOM recycles these auxin-efflux carriers towards the basal plasma membrane. Without these carriers, auxin would not be able to accumulate towards the basal end. When this gene is removed, what is left is a plant that was not able to designate an apical and basal end, thus, shoots and roots did not form.

Reference(s):

Role of the GNOM gene in Arabidopsis apical-basal patterning--From mutant phenotype to cellular mechanism of protein action | NIH

Image Source(s):
Embryogenesis | Universitas Brawijaya

]]> 2021-05-26 12:30:14 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561116651 Phototropism joaquinmigueljoyassci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561191392 Another equally important tropism of plants is their responses to light! When a certain side of the plant is irradiated, the growth hormone auxin is redistributed to the shaded side. This promotes growth of that portion, making it grow faster than the lightened areas and causing the shoot to "bend" towards the source of light! This is known as differential growth, seen on the differently irradiated sides of the shoot.

Image Source(s):
Topic 9.3: Growth in Plants | Mun-IB]]> 2021-05-26 12:54:40 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561191392 Shine a Light reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561266440 Although it is known that plants need light in order to grow and make their own energy, certain types of light are also able to help seeds break dormancy. An example of this is Brachypodium distachyon or stiff brome. This monocot is aided by red light (600–700 nm) to promote seed germination. As phytochromes of the embryo are able to pick up these light signals, it is able to break out of dormancy. Additionally, far-red light (700-780 nm), would incur the opposite to B. distachyon. Instead of promoting germination, this actually counteracts the red-light, slowing down germination.

Reference(s):

The role of light in regulating seed dormancy and germination | Wiley Online Library

Image Source(s):

Brachypodium distachyon | Wikipedia

]]> 2021-05-26 13:14:50 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561266440 Take a Chill Pill reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561267961 One of the more interesting ways to break seed dormancy is the use of cold environments to signal the changing of seasons, signaling to the plant that after a period of time, their optimal growth season will start, thus, signaling for seed dormancy to break.

The humble apple tree will be our plant of interest here. In Malus domestica or apples, their seeds require a 70-90 day period of cold stratification (5°C) in order to start germination. The exact mechanism why this happens is because of the increased H2O2 content when these seeds are exposed to very low temperatures, once the maximum concentration of this H2O2 is reached, this would signal the seed to begin germinating.

Reference(s):

Dormancy removal of apple seeds by cold stratification is associated with fluctuation in H2O2, NO production and protein carbonylation level | NIH

Image Source(s):

Apple (Malus domestica) | Toxic Plants of the World

]]> 2021-05-26 13:15:14 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561267961 A Plant's Chemical Romance reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561276761 You may be surprised to find out that Nitrate, an important chemical compound for the plant to synthesis their own amino acids and proteins, but it also has another function. Nitrate is able to promote the seed germination, breaking dormancy, in many plant species and just at low concentrations! Although other environmental factors can affect the sensitivity of seeds to nitrate, this is still an important component in the germination of seeds.

One plant species that uses nitrate to break seed dormancy is the hedge mustard (Sisymbrium officinale). This plant utilizes nitrate as a signal, stimulating the start of germination.

Reference(s):

Regulation of seed dormancy and germination by nitrate | Cambridge University Press

Image Source(s):

Mustards | Botanical

]]> 2021-05-26 13:17:28 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561276761 Get to Know the Province! reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561504643 Within the central Visayas region, Bohol is known not just for their chocolate hills and tarsiers, but they also have beautiful coral reefs and plethora of different flora and fauna both endemic to the area and native to the Philippines.]]> 2021-05-26 14:10:41 UTC https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561504643 Join Us in Our Adventure reannarosarynoelsci https://padlet.com/reannarosarynoelsci/e9v9sfc8jgvsrfnm/wish/1561521592 Although there are many interesting things to look at around Bohol, the Chocolate Hills must be one of the truly notable geological formation. Aptly named, the hills turn a brown color during the dry season, making them look like large chocolate kisses. Despite this, there is still so much greenery surrounding these hills and it got us thinking, the journey of plants towards maturation is quite an interesting topic. So now, we hope you're ready to learn all there can be about how plants grow and the different ways the environment can affect their growth.

Image Source(s):

I Could Watch Time Lapses Of Seeds Growing All Day | YouTube

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