Seed priming for abiotic stress tolerance: An overview

Abstract

Heat, drought, cold, and salt stress are some of the major kinds of stresses that crops usually face under adverse weather or soil conditions. Abiotic stresses are often interrelated, either individually or in combination; they cause morphological, physiological, biochemical, and molecular changes that affect plant growth and development and ultimately yield. Various methodologies are in vogue to evolve stress-tolerant varieties either through conventional breeding or through transgenics. However, alternatively, more simple and economical practices are also in race to address this problem. Seed priming is one such farmer’s friendly techniques recommended by many researchers for better crop stand establishment and growth even under adverse conditions. The present chapter deals with different seed priming methods and their scope in mitigating stress effects. Besides hydro-, osmo-, and halopriming, the relevance of nutrient priming and redox priming techniques for stress tolerance was also discussed. Further, how seed “priming-induced” biochemical and molecular changes regulate stress tolerance was amply explained in the light of the latest research work carried in this direction. Although the phenomenon of “priming-induced” stress tolerance appears complex, the present-day advanced techniques like proteomics, genomics, metabolomics, and transcriptomics made the task much simpler to understand these events clearly at subcellular level. Since priming mimics similar events happening under stress, the same can be exploited as a model system to decipher pathways that contribute stress tolerance.