2020 Ph.D. Admissions (Interview List)

Friday Seminar by Ms. Harsha Samtani

PK Lab/ Friday/ December 20, 2019/ 3.30 pm/ Stomatal Development in Grasses and its Manipulation for efficient water Utilization.
Category: Research
Posted by: bedineel



Stomatal Development in Grasses and its Manipulation for Efficient Water Utilization

Harsha Samtani

Stomata, which represent epidermal valves, facilitate plant-atmosphere gas exchange and balance the uptake of carbon dioxide with the loss of water vapour. Therefore, understanding the regulation of stomatal development is important as plants often adjust their stomata to suit the prevailing environmental conditions. Much of our understanding regarding stomatal development comes from the work done in Arabidopsis. However, little is known about the cultivated monocotyledonous grasses, which provides majority of human nutrition. Grasses stomatal morphology is unique, featuring dumbbell-shaped guard cells flanked by subsidiary cells. Also the development is constrained to the leaf base, with stomatal pores being formed in specified cell files adjacent to veins. Interestingly, the transcription factors underpinning stomatal fate in Arabidopsis i.e., SPEECHLESS (SPCH), MUTE, INDUCER OF CBF EXPRESSION1 (ICE1) and SCREAM2 (SCRM2) are conserved in grasses as well. But recently in Brachipodium, it has been found that the function, behavior of these genes and the regulation of their protein products have been diverged. This divergence of function has helped the grasses to achieve correctly patterned stomata and in the development of subsidiary cells. Moreover, these transcription factors are inturn regulated by Epidermal patterning factors (EPFs), which controls the frequency of stomatal development. Furthermore, recent researches have shown that overexpression of an EPF1 orthologue in crops like barley, wheat and rice leads to a decrease in stomatal density and an improved water-use efficiency (WUE). Thus, it appears that manipulating stomatal frequency could provide a tool for making water efficient plants for the future drier environment.  
  • Raissig MT, Abrash E, Bettadapur A, Vogel JP, Bergmann DC (2016) Grasses use an alternatively wired bHLH transcription factor network to establish stomatal identity. Proc Natl Acad Sci USA 113: 8326-8331.
  • Hughes J, Hepworth C, Dutton C, Dunn JA, Hunt L, Stephens J, Waugh R, Cameron DD, Gray JE (2017) Reducing Stomatal Density in Barley Improves Drought Tolerance without Impacting on Yield. Plant Physiol. 174: 776-787.
  • Dunn J, Hunt L, Afsharinafar M, Meselmani MA, Mitchell A, Howells R, Wallington E, Fleming AJ, Gray JE (2019) Reduced stomatal density in bread wheat leads to increased water-use efficiency. J Exp Bot 70: 4737-4748.