Expression Dynamics of Genes and microRNAs at Different Growth Stages and Heat Treatments in Contrasting High Temperature Responsive Rice Genotypes

Abstract

The global warming-driven climate change is becoming a major challenge for rice cultivation in Asia and Africa. High-temperature stress impairs the physiology and growth of rice plant, and ultimately results in reduced grain yield. This study was aimed to decipher the physiological and molecular changes occurring during different growth stages of heat-tolerant (N22) and -susceptible (Vandana) rice cultivars under three different heat treatments. Chlorophyll content, membrane integrity, gas exchange parameters and expression of genes and miRNAs were analyzed in N22 and Vandana at seedling, vegetative, and reproductive growth stages after exposing to short and long duration of high temperature stress, and recovery. A number of genes and miRNAs showed dynamic changes in their expression patterns at different growth stages and heat treatments, highlighting the necessity to understand gene regulation before employing the genes for modification through transgenic or gene editing approaches. Predominantly N22 showed distinct and unique capability to reprogram its physiological and molecular machinery during prolonged heat stress at reproductive stage, suggesting that the dynamics in gene regulation is crucial to determine its heat tolerant ability. The study has larger implications in deploying genes for the development of heat tolerant rice cultivars through breeding, transgenic, and genome editing approaches.

Challenges and opportunities in productivity and sustainability of rice cultivation system: a critical review in Indian perspective

“…Temperature is one of the most critical abiotic factors which influences the rice production, productivity and grain quality directly. Heat stress affects rice growth and metabolism and has severe impact on all the growth phases, especially seedling and reproductive stage (Sailaja et al 2015;Bhogireddy et al 2021). In a recent study, Zhao et al (2017a) estimated the global yield loss of rice by 3.2% for every 1 °C increase in global mean temperature by compiling the extensive published results from different analytical methods.…”