From genes to jeans: New genetic insights could lead to drought-resistant cotton

As climate change intensifies, cotton farmers face increasing challenges from drought and heat. But new research offers hope for developing more resilient varieties that can maintain high yields even in water-stressed conditions.

An interdisciplinary team of researchers investigated how different cotton plants respond to drought at the genetic level in a study recently published in the journal Journal of Plant Biotechnology.They grew 22 varieties of mountain cotton (Gossypium hirsutum L.) in the low-lying desert region of Arizona, subjecting half of the plants to drought conditions. By analyzing the plants’ genes and physical traits, scientists have uncovered fascinating insights into how cotton copes with drought.

They found that two key regulatory genes, GhHSFA6B-D AND GhDREB2A-Aplay a key role in helping cotton plants cope with water stress while maintaining fiber production. These genes act like orchestra conductors, coordinating the activity of hundreds of other genes involved in drought response and fiber development.

“We were excited to find this direct link between stress tolerance and maintaining fiber performance,” said co-corresponding author Dr. Andrew Nelson, assistant professor at the Boyce Thompson Institute. “It seems that over time, cotton plants have evolved this regulatory mechanism that helps them cope with dry conditions while still producing the fibers that are so economically important.”

One of the most intriguing discoveries concerns a gene called GhIPS1-Awhich produces an enzyme important for the synthesis of compounds that protect plants from drought stress. Scientists have discovered that only one copy of this gene, inherited from cotton’s African ancestors, responds to GhHSFA6B-D.This suggests that cotton’s ability to cope with drought has ancient roots, predating its domestication.

Even more fascinating, the team identified a small genetic variation near GhIPS1-A gene that appears to affect how well cotton holds its yield under water-limited conditions. “This single DNA letter change was associated with higher fiber production in drought-stressed plants,” explained corresponding author Dr. Duke Pauli, an assistant professor at the University of Arizona. “Such small genetic differences could be valuable targets for breeders looking to develop more resilient cotton varieties.”

As climate change leads to more frequent and severe droughts in many cotton-growing regions, it is crucial to develop varieties that can thrive with less water. This research provides valuable insights and genetic targets that can guide these breeding efforts.

The study also highlights the importance of maintaining a diverse range of cotton varieties. The range of drought responses observed across the 22 types studied underscores how important genetic diversity is for crop adaptation to changing conditions.

In a world facing ever greater environmental challenges, understanding how our most important crops respond to stress at a molecular level is more important than ever. This study advances our scientific knowledge and paves the way for more resilient and sustainable agriculture in the face of climate change.

This research was funded by the National Science Foundation (PGRP and MCB) and Cotton Incorporated.