NIPGR scientists take a step closer to climate-resilient wheat

By Ratneshwar Thakur

New Delhi: Researchers at the National Institute of Plant Genome Research (NIPGR) have identified a protein that enables plants to survive high‐temperature stress (HTS) by playing a crucial role in regulating redox homeostasis and protecting photosynthetic machinery, especially chlorophyll synthesis.

HTS is a major threat for plant survival and causes crop losses worldwide. As per recent reports from the Paris Agreement on global warming, an expected 1°C rise in temperature above the pre‐industrial level has already been reached, and an additional increase of 0.5°C is expected by 2050. Particularly, several Indian regions witnessing a rise in temperature by 1.2°C above the pre‐industrial level as against 1°C in other countries, which is a major concern. Thus, the growing threat of climate change in many parts of the world, including India, are likely to have adverse impacts caused by global warming, which will ultimately lead to food scarcity.

Bread wheat is a worldwide staple food grown on more global land areas, and India is the second-largest wheat producer. Wheat grows in the winter season and they are highly vulnerable to changes in temperature.

Now, a team led by Prof. Niranjan Chakraborty from NIPGR has identified a protein Ta2CP, which plays an important role in wheat thermotolerance.

In this study, they examined the HTS-modulated adaptive responses of wheat, and to harness the hidden genetic resource for enhanced thermotolerance, his group dissected the proteome landscape of a resilient cultivar. The results of this study have been published in the Plant Journal.

According to this study, the screening for HTS-responsive targets led to the identification of a potential candidate protein – Ta2CP [the first letters (Ta) indicate the source plant, Triticum aestivum L., followed by the protein, 2‐cysteine peroxiredoxin (2CP). The role of Ta2CP protein in thermotolerance was systematically analyzed in model organisms such as budding yeast and Arabidopsis, and finally the native plant i.e., wheat.

Further, Chakraborty’s team successfully tested HTS-adaptive responses of Ta2CP by performing the heterologous complementation of a yeast mutant by Ta2CP, and expression in Arabidopsis, and thus demonstrated its role in adaptive responses. “In our study, characterization of Ta2CP-silenced and Ta2CP-overexpressing wheat plants revealed a regulated expression of Ta2CP in due course of HTS, clearly linking to stress perception and thermotolerance,” says Dr. Divya Mishra, lead author in this study.

Next, to determine the physiological functions of Ta2CP, the team investigated how Ta2CP affects the photosynthetic machinery, with specific emphasis on chlorophyll synthesis and peroxidase status, and how it influences cellular sugar-starch homeostasis.

“Our results indicate that silencing of Ta2CP leads to higher accumulation of reactive oxygen species (ROS), leading to cell death by the process of apoptosis. However, tight regulation of Ta2CP induces the activation of cell defense pathway, and acts as a safeguard against HTS‐induced cell death,” said Dr. Niranjan Chakraborty, Professor of Eminence, DBT-NIPGR, New Delhi.

This, the researchers believe, suggests that Ta2CP acts as an HTS‐sensitive antioxidant that plays an important role in thermotolerance. The findings of this study would help plant breeding roadmap, and pave the avenue for developing climate-resilient wheat in particular and crop species in general.

The research team included Divya Mishra, Shubhendu Shekhar, Subhra Chakraborty, and Niranjan Chakraborty from DBT-NIPGR, New Delhi.

(SciSoup- A Science And Technology Blog).

Journal reference: Wheat 2-Cys peroxiredoxin plays a dual role in chlorophyll biosynthesis and adaptation to high temperature. Link.