**1. Introduction**

Human's major three requirements, namely food, clothing, and shelter are mainly provided by agricultural activity. Unfortunately, the health and productivity of most agricultural crops are impacted by both biotic (insect pests and disease pathogens) and abiotic (temperature, drought, flooding, salinity, heavy metals, radiation, nutrient deficiency, and excess) stress factors. In turn, these stress factors, in isolation and/or combination, are significantly threatening global food security. In particular, abiotic stresses are responsible for about 51–82% of annual loss in yield of the major food crops in the world agriculture. Interestingly, abiotic stress impacts on agricultural crops and food security are further aggravated by the deteriorating

agro-climatic conditions [1–4]. According to the United Nations Population Division, the world population will reach 9 billion in 2037 and 10 billion in 2058 [5]. It would be far easier to feed the projected human population because most grain crops exhibit about 1% annual yield (much < world's population growth rate), and direct feeding of people shares only 55% of the world's crop calories [6, 7]. Among the major environmental challenges, the salinization of soils (soil salinity) has been inducing most land degradation, constituting a primary limit on crop health and productivity, and thus, is threatening agriculture across the world [8].
