Research Projects

Global climate change-induced extreme weather events are going to stay. As a result, we are going to witness extreme events related to drought, flash floods, and even freezing temperatures. Plants used for agriculture were brought into cultivation by ancestors without studying in detail the intricacies of the climate we face today. Our ancestors domesticated wild relatives of present-day plants without taking into consideration the adaptive traits related to stress conditions that are currently being faced by farmers. In addition to domestication, the genetic changes introduced in the recent past in the green revolution to enhance crop yield have also extricated important genes of adaptive significance from the present-day crops. Therefore, to make the food production system resilient from the vagaries of climate change, scientists working in the field need to discover new fundamental pathways that can lead to the development of improved crop varieties that are resistant to high temperature, salt, and cold stress, etc. The shoot apical meristem (SAM) in higher plants harbours stem cells at its tip, which are vital for the formation and growth of the above-ground tissue and organs. Stem cells receive signals from niches, which are positioned just below the tip of the meristem. Past studies have shown that WUCHEL, a homeodomain transcription factor expressed within the niche cells, is required for stem cell specification. Thus, stem cell niches are essential for stem cell maintenance and self-renewal. Studies have shown that WUCHEL expression within niche cells is activated in the newly emerging axillary meristem by a two-step mechanism, where the cytokinin (CK) hormone leads to signaling. Our preliminary work shows NAC062 transcription factor regulates the expression of AHK4 in the niche cells and maintains the CK signaling. Thus, NAC062 affects the niche functioning. We want to identify the protease involved in the cleavage of NAC062 using tools of reverse and forward genetics to understand how it affects the functioning of niches in higher plants. Our genetics, molecular biology, and live-imaging-based experiments will give a comprehensive understanding of the functioning of niches in normal and stressed conditions in higher plants. Keeping in view, the following objectives will be pursued: • Investigating the role of chilling stress on cell division and differentiation in the shoot apex. • Investigating the impact of cold on NAC062 cleavage and CK signalling. • Identification of factors involved in NAC062 cleavage by genetic and biochemical approaches. • Understanding the role of NAC062 target genes and their role in SAM growth. In this proposal, we would like to study the role of extreme cold on shoot apex growth & development, and also would like to understand how NAC062/NTL6 cleavage occurs in response to cold, and how it affects CK responses in order to maintain SAM growth in Arabidopsis. It has been shown that wheat seedlings treated with exogenous CK would withstand cold stress better compared to controls, and thus, crop losses resulting from damage to the shoot apices due to extreme cold stress can be minimized by external application of CK. However, this proposal would allow us to explore the mechanism in detail. The following questions will be addressed to understand the impact of extreme cold on shoot growth in this proposal. • How is SAM growth affected in cold conditions? • Is NAC062/NTL6 involved in the protection of shoots in the face of extreme climatic stress by promoting CK signalling? • Is the activity of NAC062/NTL6 and its cleavage regulated by a change in membrane fluidity or by membrane-localized proteases in response to cold?