Research Projects

Rice is an important crop grown widely in India and feeds a large percentage of the global population. It is cultivated in tropical areas with high humidity and is extremely vulnerable to environmental fluctuations. Since there have already been significant changes in temperature and water ecosystems worldwide, the Intergovernmental Panel on Climate Change (IPCC) recommends addressing adaptation of organisms as an immediate action. A process critical for reproductive success of rice is the transmission of pollen from the male anther to the female stigma. This transfer occurs through the environment and is sensitive to conditions the plant is exposed to. Upon stimulation by the stigma, the pollen forms a tube to carry the male gametes to the female gametophyte for fertilisation. The transport of gametes is mediated by the plant cytoskeleton, composed of filaments like actin and microtubules. The gametes are enclosed within a microtubule cage and transported on cortical actin bundles by crosslinking protein- kinesin with calponin homology domain 1 (KCH1). The goal of my research is to examine the effect of temperature and dehydration on cytoskeleton-mediated transport of gametes within the pollen tube. It is difficult to examine the above effects due to a lack of molecular understanding of the process. Hence, the first objective of the project is to decipher the mechanism of crosslinking and transport by KCH1 from rice. This will be carried out using an in vitro approach where the dynamics and structure of cytoskeletal filaments assembled from purified rice tubulin will be investigated in the presence of recombinantly purified KCH1. Imaging techniques such as total internal reflection fluorescence microscopy (TIRF) and cryo-electron microscopy (cryo-EM) will be used to examine filament properties at different spatial scales. The resulting information will guide the next objective involving a methodical investigation of the effect of simulated stresses on filament interactions. To evaluate the above findings in a cellular context, a framework to image filament-based transport in elongating rice pollen tubes using fluorescence microscopy will be simultaneously developed. Defects in the transport of gametes, when subjected to unfavourable conditions, will then be investigated using bright field and fluorescence microscopy. The results from this study will provide fundamental insights into the largely unexplored area of plant cytoskeletal organisation. Further, by combining precise in vitro measurements with cellular imaging, we aim to provide the first comprehensive picture of gamete transport in plants. Our effort to understand the effect of environmental stresses on a critical aspect of rice plant growth presents opportunities to enhance crop survival in rapidly varying environments. Increased survivability of plants such as rice will help achieve the United Nation’s sustainable development goals of food security and cleaner environments.