3MBIO7 Justo & Santiago PlantArea Palawan by https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb en-us 2021-05-25 14:19:33 UTC 2024-10-01 01:01:31 UTC hello@padlet.com https://padlet.net/icons/png/1f331.png johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1557798413 Seed banks are a collection of seeds that are reserved for the future. It is important since these seeds are the backups in case of catastrophes occurring, where plant life may be devastated. Seed banks essentially safeguards the species of plants that are being kept and prevents their extinction. Usually, the seeds stored in these seed banks are of economic importance, such as agricultural crops. In the Philippines, there are seed banks, however, they are set up for farmers to have a cheaper source of their seeds, not as a reserve in case of disasters.]]> 2021-05-25 14:26:17 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1557798413 PART B: Embryogenesis and Seed Germination, Dormancy, and Seedling Establishment johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1559635490 image retrieved from: Mukherjee (2020)]]> 2021-05-26 00:14:33 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1559635490 Embryogenesis johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1560752131 Plant embryos have different stages of embryonic development.  The embryogenesis of a monocot and a dicot embryo are similar in the early stages. The main difference between the two embryos is in the number of cotyledons.]]> 2021-05-26 08:57:32 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1560752131 Seed Dormancy johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1560755601 Seed dormancy is a mechanism that prevents the germination of the seed. It is important for the plant's survival since it prevents germination during unfavorable conditions, such as extreme temperatures, flooding, etc. There are multiple types of seed dormancy. One example is known as coat-imposed dormancy. It involves the seed coat causing the seed's dormancy through multiple means, such as preventing water entry. This can be observed in legumes such as clover (Trifolium spp.). Preventing the entry of oxygen can also cause seed dormancy, which can be observed in the wild mustard (Sinapis arvenis). The seed coat can be too thick or tough for the radicle to penetrate; this can be observed in tomatoes, coffee, and tobacco. The seed coat can also prevent the inhibitory secondary metabolites (phenolic acids, tannins, and coumarins) from leaving the seed. To promote germination in seeds showing coat-imposed dormancy, scarification techniques should be done. Another type of dormancy is embryo dormancy, where the embryo within the seed is too immature for it to germinate, causing dormancy, this can be observed in celery and carrot. The solution for this is to wait for the embryo to develop and wait for germination. Another type of embryo dormancy is the cotyledons inhibiting seed germination; the cotyledon should be removed to promote germination. Plants that demonstrate this type of dormancy include the European hazel (Corylus avellana) and European ash (Fraxinus excelsior). Other general methods to promote germination include providing an environment that has the conditions and needs such as nutrients and light for the plant.]]> 2021-05-26 08:59:32 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1560755601 johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1560756363 2021-05-26 08:59:55 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1560756363 Stages of embryonic development of Monocot and Eudicot alyssajulia_justo_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561676150 2021-05-26 14:51:29 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561676150 Establishment of apical-basal axis alyssajulia_justo_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561743452 The apical-basal organization of plant tissues and organs is established very early in embryogenesis. The diagram below shows how the organs of the early Arabidopsis seedling originate from specific regions of the embryo.

 The GNOM gene helps establish apical–basal polarity, while the MONOPTEROS gene is necessary for basal patterning and formation of the primary root]]> 2021-05-26 15:07:47 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561743452 Establishment of radial axis alyssajulia_justo_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561765281 The radial tissue patterns are also established during embryogenesis. The diagram shows the origin of different tissues and organs from embryonic regions in Arabidopsis embryogenesis.


SHORT ROOT (SHR) and SCARE- CROW (SCR) genes, are necessary for tissue differentiation and cell differentiation not only in the embryo, but also in both primary and secondary roots and in the hypocotyl. Mutants of SHR and SCR both produce roots with a single-celled layer of ground tissue .]]> 2021-05-26 15:13:13 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561765281 Palawan johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561832390 Palawan is an archipelagic island in the region MIMAROPA. It known to have a rich biodiversity and home to multiple species of flora that is endemic to the island.
Image retrieved from Schoppe (2010)]]> 2021-05-26 15:28:34 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561832390 Plants for the Seed Bank johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561844100 The plants that will be included in the seed bank will be:
  • Phaleonopsis amablis
  • Paphiopedlium argus
  • Euanthe sanderiana (Waling waling)
  • Cycas curranii (Curran's pitogo)
  • Cycas wadei
  • Platycerium coronarium (Staghorn fern)
  • Agathis philippinensis (Almaciga)
  • Areca ipot (Bungang-ipot)
  • Pemphis acidula (Kabantigi)

  • Nepenthes attenboroughii

These plants will be selected to be part of the seedbank due to them being endangered due to habitat loss. (Grant, 2020) These plants may become extinct in the island and there may still be more to learn about them. With the help of the seed bank, it can safeguard the future of these plants. However, the seed bank will not be limited to these plants since there are many more species that are still in danger.
]]> 2021-05-26 15:31:20 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561844100 johnloui_santiago_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561849298 Grant, B. (2010). List of Ten Endangered Plants in Palawan. Garden Guides. https://www.gardenguides.com/122859-rare-plants-mauritius.html

Mukherjee, S. (2020). Parts of a Seed, Their Structure, and Functions with Diagram. Science Facts. Retrieved from: https://www.sciencefacts.net/parts-of-a-seed.html

Hadas, A. (2005). GERMINATION AND SEEDLING ESTABLISHMENT. Encyclopedia Of Soils In The Environment, 130-137. doi: 10.1016/b0-12-348530-4/00149-1

Schoppe, S., Matillano, J., Cervancia, M., & Acosta, D. (2010). Conservation Needs of the Critically Endangered Philippine Forest Turtle, Siebenrockiella leytensis, in Palawan, Philippines. Chelonian Conservation and Biology, 9(2), 145–153. https://doi.org/10.2744/ccb-0783.1

Sen, A., & Puthur, J. (2020). Seed priming-induced physiochemical and molecular events in plants coupled to abiotic stress tolerance: An overview. Priming-Mediated Stress And Cross-Stress Tolerance In Crop Plants, 303-316. doi: 10.1016/b978-0-12-817892-8.00018-0

Taiz, L., & Zeiger, E. (2010). Plant physiology. Sinauer.]]> 2021-05-26 15:32:35 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561849298 Tropisms alyssajulia_justo_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561850409 Auxin is a growth regulator that has multiple roles in plant growth and development, including embryo axis formation, vasculature development, lateral root formation and development, apical dominance, and tropisms.

Phototropism is the growth in response to light. It is expressed in all shoots and some roots, ensuring that leaves receive adequate sunlight for photosynthesis. The gradient in phototropin phosphorylation, according to the hypothesis, causes auxin to migrate to the shaded side of the coleoptile. When the auxin reaches the shaded side of the tip, it travels basipetally to the elongation zone, where it stimulates cell elongation.

Gravitropism, or growth in response to gravity, allows roots to grow downward into the soil and shoots to grow upward away from the soil, which is important during the early stages of germination.
Gravitropism involves the lateral redistribution of auxin. Early experimental evidence suggests that the coleoptile tip can detect gravity and redistribute auxin to the lower side.

Thigmotropism, or touch growth, allows roots to grow around rocks and is responsible for climbing plant shoots' ability to wrap around other structures for support.]]> 2021-05-26 15:32:51 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561850409 Water imbibition alyssajulia_justo_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561855609 Water imbibition by seeds prior to germination can be divided into three phases: rapid water uptake (phase I), enhanced water uptake (phase II), and water uptake concurrent with growth initiation (phase III) (phase III) (Sen & Puthur, 2020). Water is distributed in the seed cover's crevices, cracks, and flaws during phase I and is absorbed by the seed tissues. Measurements of water uptake rates during this phase demonstrate that these rates are temperature-dependent and are accompanied by increases in respiration rate and light sensitivity in some seed species (Hadas, 2005).]]> 2021-05-26 15:34:02 UTC https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561855609 How food reserves are mobilized alyssajulia_justo_sci https://padlet.com/johnloui_santiago_sci/5po39m0ro0vyr9bb/wish/1561856768
During germination and early seedling growth, hydrolytic enzymes (α- and  β-amylase) break down the endosperm's stored food reserves, and the solubilized sugars, amino acids, and other products are transported to the growing embryo.  Internally,  α-amylase hydrolyzes starch chains to produce oligosaccharides composed of -1,4-linked glucose residues.  β-amylase degrades these oligosaccharides from the ends, resulting in maltose, a disaccharide. Maltose is then converted to glucose by maltase.  

Gibberellic acid could act in place of the embryo to stimulate starch degradation. The embryo regulates the mobilization of its own food reserves during germination by secreting gibberellins, which stimulate the digestive function of the aleurone layer which functions in hydrolytic enzyme synthesis and release.
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