Understanding the Molecular Mechanism of Plant Regeneration in Tropical Aeroponic System

Project Number
RI 3/13 CZ

Project Duration
May 2014 - May 2017

Status
In-Progress

Abstract
Plants have remarkable capability to regenerate new organs after wounding. In response to wounding, adult somatic cells often change from differentiated to less differentiated states, forming a specialized tissue named callus containing a group of cells with proliferative competence. Callus is capable of differentiating into any plant organ to replace the missing parts from the wound. Such processes of dedifferentiation and subsequent redifferentiation are regulated by two important plant phytohormones, auxin and cytokinin. In recent years a set of key genes (WUSCHEL, CUC2, WIND1) mediating plant regeneration has been identified from the model plant – Arabidopsis thaliana, which grows naturally throughout temperate regions of the world. Most of the Arabidopsis research was performed under the growth condition similar to Arabidopsis’ natural habitat, but how plants regenerate in tropics is poorly understood. As such, studying the impact of temperature on plant regeneration is of particular interest, not only in fundamental plant biology, but also in agricultural biotechnology. Arabidopsis belongs to the Brassicaceae (mustard or crucifer) family which includes widely cultivated green leaf vegetables such as cauliflower, cabbage, and broccoli. There are numerous examples where the knowledge derived from Arabidopsis research was successfully applied to improve vegetable farming. To meet Singapore’s goal of sustaining food security, A/P He Jie developed the areoponic farming system to grow temperate vegetable in tropical greenhouse. By cooling the root zone only, a few vegetables such as lettuce, Chinese broccoli and Chinese cabbage have been successfully grown. One notion is that the root architecture is fully developed and optimized under such areoponic farming system; however the whole mass of root is abandoned after the shoot part of the vegetable is harvested. Alternatively, if the regeneration of the vegetable is under elegant control, after cutting away the shoot part, new meristem and leaves would continuously grow out utilizing the existing root. Then repeat harvest could become feasible. By doing this, we can save the time and labour from seed germination to seeding growth, until full development of the mature root, as well as the cost of energy and nutrient supply. The proposed project firstly attempts to understand the mechanism of plant regeneration using Arabidopsis in tropical aeroponic system. Then we compare vegetable species with Arabidopsis for common features in regeneration. Finally, we aim to engineer synchronized regeneration of temperate vegetables to achieve repeat harvest under tropical aeroponic system.

Funding Source
NIE

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