Seed Priming: A Feasible Strategy to Enhance Drought Tolerance in Crop Plants

Abstract

Drought is a serious threat to the farming community, biasing the crop productivity in arid and semi-arid regions of the world. Drought adversely affects seed germination, plant growth, and development via non-normal physiological processes. Plants generally acclimatize to drought stress through various tolerance mechanisms, but the changes in global climate and modern agricultural systems have further worsened the crop productivity. In order to increase the production and productivity, several strategies such as the breeding of tolerant varieties and exogenous application of growth regulators, osmoprotectants, and plant mineral nutrients are followed to mitigate the effects of drought stress. Nevertheless, the complex nature of drought stress makes these strategies ineffective in benefiting the farming community. Seed priming is an alternative, low-cost, and feasible technique, which can improve drought stress tolerance through enhanced and advanced seed germination. Primed seeds can retain the memory of previous stress and enable protection against oxidative stress through earlier activation of the cellular defense mechanism, reduced imbibition time, upsurge of germination promoters, and osmotic regulation. However, a better understanding of the metabolic events during the priming treatment is needed to use this technology in a more efficient way. Interestingly, the review highlights the morphological, physiological, biochemical, and molecular responses of seed priming for enhancing the drought tolerance in crop plants. Furthermore, the challenges and opportunities associated with various priming methods are also addressed side-by-side to enable the use of this simple and cost-efficient technique in a more efficient manner.

Seed Priming with Phytohormones: An Effective Approach for the Mitigation of Abiotic Stress

“…Exogenous application of ABA to plants also stimulates the regulation of stomatal movements, which helps reduce transpirational water loss. Marthandan et al [ 120 ] reported priming Arabidopsis seeds with amino-butyric acid enhanced drought tolerance by accumulation of ABA and the closing of stomata. However, it is not known how seed priming with ABA helps regulate stomatal movements in plants.…”

Efficacy of KNO3, SiO2 and SA priming for improving emergence, seedling growth and antioxidant enzymes of rice (Oryza sativa), under drought

“…Priming of seeds is an easy, affordable and safe technique for enhancing emergence, seedling growth, yields and drought stress tolerance of crops 13 . It is a controlled hydration technique that stimulates pre-germination metabolic processes such as increased water imbibition, activation of reserve mobilizing amylase, cellulase and xylanase within seeds without actual germination 13 , 14 . Priming of seeds has been shown to stimulate faster emergence rates, faster seedling establishment and vigorous seedling growth.…”

Effects of hydrogen peroxide application on agronomic traits of rice (Oryza sativa L.) under drought stress

“…Besides, genes related to protein synthesis, carbohydrate metabolism, and signaling were up-regulated at the late imbibition stage. Marthandan et al (2020) proposed that the seed priming method can induce physiological adaptation, which in turn increases crop yield under drought stress. In the review, the stress memory left in the seed can faster, and stronger activate the gene and transcription after post-germination.…”