Seed banks provide a means of preserving historical and cultural value; in this sense, seed banks are similar to seed libraries, storing crucial information. It guards against the extinction of rare plant species' genetic diversity. Moreover, seed banks are referred to as a primary preventive measure often if something goes wrong. They're designed to prepare for radioactive fallout, catastrophes, and disease outbreaks. Our crops have become less genetically diverse due to industrialization and thus became less adaptable to the surroundings. Seed banks help to protect the genetic diversity of the world's plants (Vernooy et al., 2020).

In the Philippines, there are efforts being made to successfully establish a seed bank. In fact, our country is considered to be one of the pioneers of community seed banks. The Cordillera Ecological Center, better known as PINE TREE, has developed four community seed banking sites with the sole purpose of meeting food security in support of the global seed banking movement. It operates in the Cordillera Administrative Region, made up of several indigenous communities, especially the Igorots (Bengwayan, 2020). 

Although not as big and as widely known as the other seed libraries in the world, it is already a huge step to actually have community banks in the country. If further improved, focused, and funded on, it is without a doubt that people would invest and see its importance more.

Proembryo stage. As compared to dicots, monocots have a more complex embryo structure in the mature seed, but early embryo development is identical. The proembryo, globular, scutellar, and coleoptilar stages of embryogenesis occur in monocots. The first cell division after fertilization is asymmetrical, resulting in an apical and basal cell take, for an instance, in corn (Zea mays). The embryo develops from the apical cell, which divides faster than the basal cell.

Globular stage. In contrast to dicots, the suspensor does not consist of a single or double row of cells, and the proembryo in the globular stage is less distinct. The outer epidermal layer is evident in the late globular stage, and a group of cells on one side of the proembryo divides at a faster rate. The embryo axis will emerge from this.

Scutellar stage. The cotyledon is still visible in the scutellar stage of growth. Monocots also replaced the two cotyledons found in dicot embryos with a single modified cotyledon known as the scutellum. Along with the endosperm and embryo axis, the scutellum functions as a conductive tissue.

Coleoptilar stage. The embryo axis differentiates into the radicle and plumule. The embryo axis of monocots also has specialized tissue around the shoot and root tissue to assist in germination. Respectively, these are the coleoptile and coleorhiza.

Figure adapted from the University of Florida (n.d).

According to the Royal Tasmanian Botanical Gardens (2012), there are three types of seed dormancy and these are the following: physical, physiological, and morphological. In physical, the dormancy caused by an impervious seed coat. Physical dormancy is caused by impermeable layer(s) that form during seed or fruit maturity and drying. Moreover, when embryos are inhibited from growing and seeds from germinating until chemical changes take place. When the germination rate increases following an administration of gibberellic acid or after a period of inactivity, this is a sign of physiological dormancy. Lastly, morphological  dormancy where embryo is undeveloped or undifferentiated. Some seeds have completely differentiated embryos that need to expand more before seed germination, whereas others have not yet differentiated into distinct tissues when the fruit ripens.

There are techniques on how to break the seed dormancy and this is involves scarification as the one we did in the laboratory. This involves the mechanical, hot water, and chemical scarification. These techniques are done so as to encourage germination. Mechanical scarification is a process that involves manually scarring the seed's surface in order to promote water absorption. Thermal scarification, also known as hot water scarification, is performed by temporarily exposing seeds to hot water. Lastly, chemical scarification involves using one or more chemicals to stimulate germination, which is another type of scarification. It may entail ingesting or soaking seeds for varied periods in very concentrated acidic or basic solutions (Yildiz, 2017).

As the proembryo divides further, it takes on a spherical shape referred to as the globular stage. This is noted to be the first stage of the embryo proper. Following that, cotyledons emerge from the embryo, forming the heart stage. Cotyledons, which are embryonic leaf-life structures, perform functions such as food preservation, absorption, and photosynthesis. As the cotyledons elongate and the embryo's base thickens, a torpedo emerges. Cell division is concentrated at the shoot apical meristem, which is situated between the cotyledons at the shoot tip, and the root apical meristem, which is located at the embryo's most bottom portion.

The mature embryo is the product of the final stage of embryogenesis. The radicle is an embryonic root found in the mature embryo. At this stage, the embryo goes inactive, halting cell division and metabolic activities. The seed has gotten to the point that it can be dispersed. Development resumes once the seed germinates and the embryo develops into a seedling. Endosperm cells divide in some eudicots and endosperm fills a large portion of the mature seed.

The endosperm serves as storage for nutrients. Some non-endospermic eudicots, like Capsella bursa-pastoris, grow endosperm first, but the nutrients are then digested and transferred into the two cotyledons. The growing seedling relies on the food reserves contained in the cotyledons and endosperm before the first set of leaves starts photosynthesis after germination.

Embryogenesis phases in the ovule of the shepherd's purse (Capsella bursa-pastoris). The zygote divides into an apical cell and a basal cell after fertilization. The apical cell divides to form a proembryo before dividing again to form the embryo proper. The suspensor is formed when the basal cell divides. The embryo is in the globular stage (a), which is characterized by a spherical mass of cells developing within the oval-shaped ovule. The embryo proper reaches the heart stage (b) when the cotyledons emerge, which resembles a heart due to the two cotyledons. In the torpedo stage, the embryo's base widens to form a cylindrical hypocotyl, and the cotyledons begin to bend (c). The embryo's cells develop in vertical columns (as seen from the Figure below) (Ha et al., 2021).

[2] Baskin CC, Baskin JM. Germination ecology of seeds with nondeep physiological dormancy. In: Baskin CC, Baskin JM, editors. Seeds: Ecology, Biography, and Evolution
of Dormancy and Germination. San Diego, California: Academic Press; 1998. pp. 57-64

[3] Bengwayan, M. (2020). Philippine Indigenous NGO Seed Banking For Food Security – OpEd. Retrieved 24 May 2021, from https://www.eurasiareview.com/10122020-philippine-indigenous-ngo-seed-banking-for-food-security-oped/

[4] Boesewinkel F.D., Bouman F. (1984) The Seed: Structure. In: Johri B.M. (eds) Embryology of Angiosperms. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-69302-1_12

[5] Bradbeer J.W. (1988) Seed Structure and Composition. In: Seed Dormancy and Germination. Tertiary Level Biology. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-7747-4_3

[6] Chua-Barcelo R. T. (2014). Ethno-botanical survey of edible wild fruits in Benguet, Cordillera administrative region, the Philippines. Asian Pacific journal of tropical biomedicine, 4(Suppl 1), S525–S538. https://doi.org/10.12980/APJTB.4.201414B36

[7] Ganzon, F. G. (2011). Sustainable forest management of Benguet pine in the Cordillera, Philippines.

[8] Ha, M., Morrow, M., & Algiers, K. (2021). 18.1: Embryogenesis. Retrieved 22 May 2021, from https://bio.libretexts.org/Bookshelves/Botany/Botany_(Ha_Morrow_and_Algiers)/Unit_3%3A_Plant_Physiology_and_Regulation/18%3A_Development/18.01%3A_Embryogenesis

[9] New agriculturist. (n.d.). Retrieved May 26, 2021, fromhttp://www.new-ag.info/en/focus/focusItem.php?a=456

[10] Royal Tasmanian Botanical Garden. (2012). Retrieved 24 May 2021, from https://gardens.rtbg.tas.gov.au/index.aspx?base=308

[11] Seeds, Embryogenesis. Retrieved 20 May 2021, from https://propg.ifas.ufl.edu/04-seeds/01-development/04-seedsdevelopment-embryogenesis.html

[12] Tacloy, J. G. (2015). Species Profile and Associated Indigenous Knowledge of Trees and Shrubs Used as Tea in Benguet. Mountain Journal of Science and Interdisciplinary Research (formerly Benguet State University Research Journal), 73, 1-18.

[13] Taiz, L., Zeiger, E., Møller, I. M., & Murphy, A. (2015). Plant physiology and development (No. Ed. 6). Sinauer Associates Incorporated.

[14] Vernooy, R., Mulesa, T. H., Gupta, A., Jony, J. A., Koffi, K. E., Mbozi, H., … Wakkumbure, C. L. K. (2020). The role of community seed banks in achieving farmers’ rights. Development in Practice, 1–14. doi:10.1080/09614524.2020.1727415

[15] Woodstock, L. (1988). SEED IMBIBITION: A CRITICAL PERIOD FOR SUCCESSFUL GERMINATION. Journal of Seed Technology, 12(1), 1-15. Retrieved May 25, 2021, from http://www.jstor.org/stable/23432691

[16] Yildiz, M., Beyaz, R., Gursoy, M., Aycan, M., Koc, Y., & Kayan, M. (2017). Seed Dormancy. Advances in Seed Biology. doi:10.5772/intechopen.70571

[17] Zhao, P., Begcy, K., Dresselhaus, T., & Sun, M.-X. (2016). Does Early Embryogenesis in Eudicots and Monocots Involve the Same Mechanism and Molecular Players? Plant Physiology, 173(1), 130–142. doi:10.1104/pp.16.01406 

The body plan of the adult organism is determined by the apical-basal axis of the early plant embryo. Plants have evolved a unique process that utilizes directed, cell-to-cell transport of the growth regulator auxin to generate a polarized embryonic axis. PIN auxin transporters, whose polar subcellular location dictates flow directionality, are responsible for auxin transport. The auxin response machinery, which contributes to embryo patterning processes, is mediated by PIN-mediated auxin transport, which mediates the spatial and temporal activity of the auxin response machinery, which includes the establishment of the apical (shoot) and basal (root) embryo poles. 

As cell division occurs, the apical-basal and radial axes continue to develop. Differentiation will continue to exist. Radial patterning occurs in angiosperms during the globular stage and results in the creation of three tissue systems. The axial pattern is determined by the heart stage or the shoot-root axis (Wabnik et al., 2013)

It begins in water uptake by the dry seed and ends with the culminating embryonic axis, usually the radicle, from its surrounding tissues or seed coat. Germination is not a seedling growth after the occurrence of radicles. establishment of a seedling. It requires water, temperature, and oxygen, and often light and nitrate in right amounts. Hence, water is the most important factor and water uptake is needed for turgor pressure that powers cell expansion and serves as the basis of vegetative growth and development.

Three Phases that corresponds to phases of water uptake

In the first phase, the flow of water corresponds with water potential gradient between the environment and the seed. As water enters the seed, it will cause an increase in size due to  turgidity. As the food reserves are hydrated and will become usable form by the plant.

For the phase 2, Tropism is the ability of an organism to move towards a stimulus and inhibits the light from the sun with the help of auxins. Shoot will then grow faster and it can bend through the light through phototropism, the plant's response to light. Thus, making the plant grow towards the light and away from shaded areas and due to the amount of auxins it inhibits. Through gravitropism which a plant, the roots are positive gravitropic while the stems are negative gravitropic this is because roots are more favorable without light than the shoot part.  Whereas, auxin will accumulate at the bottom part part the root making the the upper section grow faster. This will directly anchor to the soil downward.

Lastly in phase 3, water uptake resumes due to decrease in water potential, suggesting that food reserves and seedling grows are fully mobilized. This is because seed has its food stored in the starch found in the endosperm. As the embryo grows, it will then release gibberellic acid into the endosperm and will diffuse into the aleurone layer. The enzymes will degrade the starch to be transported to the developing plant embryo.