Cross-Talk between Phytohormone-Signalling Pathways under Abiotic Stress Conditions

Environmental stresses, especially abiotic stress significantly reduce crop growth and harvests. There is an utmost need to develop approaches that could reduce crop losses to meet the food, feed, and fibre demands of increasing populations. Therefore, one must understand the mechanisms involved in plants to counteract the harmful effects of abiotic stresses. Plants are sessile; however, their good plasticity allows them to adapt to adverse environmental conditions by a complex signalling network. Abiotic stresses activate the signal transduction cascade that interacts with the baseline of phytohormone pathways transduction. Phytohormones play a key role in improving the plant's ability to adapt to adverse environmental conditions by supporting growth, development, nutrients allocation, sink/source transitions, and response to abiotic stresses. The points of convergence between the hormonal signalling transduction are considered crosstalk, and, collectively, they form a signalling network. The crosstalk between different phytohormones leads to synergistic or antagonistic interactions, which play a vital role in the balance between plant response to abiotic stress and plant growth and defence. The current chapter highlights the crosstalk between phytohormone signalling under various abiotic stresses. Based on these results, an abiotic stress signalling model will be built, which contains the most common signalling components in abiotic stresses and is therefore associated with the development of stress tolerance. Thus, the problem of feeding the increasing global population will be solved.