Understanding Pollen Behaviour under High Temperature for Climate Resilient Breeding

Abstract

Global warming raise challenges for plant reproduction as pollen development and functioning are the most heat-sensitive processes. Hence, it is crucial to understand the mechanisms and processes underlying heat-related male sterility in order to maintain food security. Elevated temperatures elicit acclimation responses that permit pollen development under restricted heat stress conditions; physiological injury leading to pollen development and functioning failure occurs at higher temperature stress. Pollen and the surrounding anther tissues respond to increased temperature at the transcriptome, proteome, and metabolome levels. To counteract the damaging effect of misfolded proteins under heat stress, HSPs (Heat Shock Proteins) accumulate in the cytoplasm and organelles to stabilize, resolubilize, and refold proteins. The pathways leading to the production of carbohydrates, amino acids, phenolic compounds, polyamines, hormones and lipids are interconnected and contribute to the metabolic homeostasis required for the growth and viability of the pollen. The pathways leading to the production of carbohydrates, amino acids, phenolic compounds, polyamines, hormones and lipids are interconnected and contribute to the metabolic homeostasis required for growth and viability of the pollen. Using molecular markers to access specific genomic regions associated with a specific trait along with QTL (Quantitative Trait Loci) fine mapping can identify several candidate genes associated with thermo-tolerance.  A deep understanding of the molecular mechanisms and metabolic processes involved in the stress response to high temperatures in flowers and particularly in the male reproductive organs will be a major step towards developing of effective breeding strategies for high and stable production in crop plants.