Aparna Nautiyal

Present and future food security is a censorious issue aggravated by the upshot of climate change on agriculture. Plant distribution, growth and productivity are critically affected by various environmental stresses both biotic and abiotic depending upon the source, jasmonic acid (JA) is an organic molecule, derived from alpha-linolenic acid (called lipid-derived signalling molecule involved in many regulatory pathways). It has gained a lot of attention in establishing its role in several abiotic stresses such as heat and salinity, including others. It plays a protective role through both physiological and molecular responses, which include reducing stomatal opening and closing in case of drought stresses, activating the antioxidant system in case of ROS production and others involving the accumulation of several amino acids and sugars. It does not work as an independent regulator but acts synergistically with other PGRs involving complex interactive crosstalk. Repressor proteins (jasmonate zim domain protein and MYC2) are the key components mediating the crosstalk. In this chapter, the defensive mechanisms of JA, which help plants acclimatize to these stresses, are documented along with a brief discussion on the various signalling pathways involved, thereby resulting in plants with enhanced tolerance to environmental conditions and addressing agriculture and breeding problems.

Phytohormones are small chemical messengers and key players that regulate plant growth and development as well as responses to biotic and abiotic stress factors that maintain plant homeostasis and allow adaptation to environmental changes. Plants possess the ability to produce various compounds that activate the expression of stress-related genes encoding products to protect their cellular components from the adverse impact of abiotic stresses. Extensive studies are being conducted on both traditional (auxin, cytokinin, gibberellin, ethylene, abscisic acid) as well as non-traditional (salicylic acid, jasmonates, strigolactones) hormones to understand the molecular interaction, mechanisms and crosstalk. Exogenous applications of phytohormones to impart tolerance against stresses are also being experimented with. Recently, the role of miRNAs in some stresses has been identified by regulating various phytohormone signaling pathways and by targeting several transcription factors (TFs) and defense-related genes. Emerging research based on priming techniques can be used as a practical management tool in agriculture to overcome the adverse impact of abiotic stress, improving cellular homeostasis and the growth of plants. This chapter focuses on the recent studies conducted to understand the role of numerous phytohormones in alleviating plants' tolerance to stresses.

Editorial: A wonder legume, soybean: prospects for improvement

The concept of omics-based technological approaches has promoted translational research by integrating knowledge from diverse areas to understand their dynamics by exploring the molecular mechanisms underlying various processes paving the way for further improvements in the crops quality by providing sound knowledge on controlling plant diseases. This area is not profoundly investigated a decade back and hence this knowledge has become exceedingly important in modern times as it has got potential for being utilized in crop improvement programs. In this review, the contributions of different omics technologies including genomics, transcriptomics, proteomics, and metabolomics in understanding and materializing the ways involved in the plant pathogen interaction (PPI) is discussed. Furthermore, opportunities, challenges, and perspectives of omics linked to signaling mechanisms have also been highlighted that are significantly linked to plant-microbe interactions.