Morpho-physiological dynamics of plants to heat stress and Si induced thermo-tolerance

Abstract

Heat stress, resulting from global warming, is the foremost abiotic risk to crop development,

yield and productivity. Heat stress adversely affects plant growth and development at every

stage of their life cycle, from germination to reproductive development, fueling food

insecurity. Therefore, sustainable and eco-friendly solutions are needed to make plants

resilient to heat stress. Plants respond to heat stress by initiating a series of physiological,

biochemical, and molecular response and adapt by activating many stress-responsive genes.

Cuticles, helps the plants to reduce the absorption of solar radiation. Intensive transpiration in

well hydrated plants also protect the plants from heat stress. Recent findings have established

Silicon (Si) as an essential stress relieve element in plants, which protect it against numerous

biotic and abiotic stresses. It is involved in root growth, transportation and uptake of essential

nutrients, activities of key enzymes, carbon assimilation, enhance ROS scavenging, upregulate

the linker histone, and modulates intercellular signaling by triggering phyto-hormones and

antioxidant enzymes. Si has indirect effect on the expression of stress-responsive transcription

factors and stress-associated genes and proteins like heat shock proteins (HSPs) which is

involved in modulating the tolerance of the plant under stress. Technological advancement has

enabled the in-depth characterization of Si involvement in flowering, pollen tube growth, and

fertilization. Transcriptomic analysis has revealed the large number of Si-responsive

transcripts, highlighting its regulatory role at molecular level. In the present scenario, there is

a need for developing Si-based technology to enhance plant tolerance against heat stress

without compromising plant growth and quality. Therefore, this review focus on the adverse

effect of heat stress on plants and highlighted recent advancements of Si induced heat tolerance

in plants and how Si can effectively contribute to crop production and act as a bio-stimulant

for future-oriented sustainable agriculture under raising threat of climate change.