Assessment of Irradiation Stress in Crop Plants with Modern Technical Advances

Abstract

It is their necessity for sustaining the crop productivity especially under the adverse condition of environmental impacts to meet the ever-increasing human population. The unfavourable environmental conditions especially with climate change force the selection of crop genotypes with a sustainable practice for better and higher productivities. Light is the crucial environmental inputs that set a bottleneck for the growth of the plants through low and/or excess irradiation. Photosynthesis is a multifaceted physiological phenomenon that solely depends on the quality and quantity of irradiance under any ecological niche that concerns the carbon dioxide (CO2) fixation and regulation of photorespiration. With different hierarchies of light requirement in photosynthesis, the induced photooxidation is the key to regulate the constitution of the photosynthetic organelle and its proper functions. Photochemistry with its successful utilization of irradiance is often limited by the loss of energy with higher wavelength as fluorescence. It is the realization of the plant scientists to consider the fluorescence as a valve to reduce the photooxidation and its consequences to the loss of carbon through photorespiration. Identification of specific genes imparts the structural and functional integrities of both the photosystems, their modalities in regulation and variations in C3 and C4 species at the insights for photosynthetic improvements at the molecular level. Moreover, the promising direction for CO2 photoassimilation leading to the mechanism of carbon concentration also opens up the possibilities of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO) in proper functioning, particularly under high irradiation stress. Undoubtedly, it is next to impossible to transfer the C4 trait into C3 into precise manner; however, improvisation of CO2 concentration on RuBisCO is fixed. Therefore, the modern state of the art in increasing photosynthetic efficiency is based on proper utilization of irradiation by more into photochemistry, reducing the photooxidation, prone to RuBisCO more into carboxylation and partitioning of photoassimilates into cellular constituents which are the spaces for crop improvement. Thus, the review is intended to improve the techniques and approaches for photo-synthetic activities with possible and feasible directions by which sustenance crop growth and productivity may be assured under irradiation stress.