The Response of Maize Physiology under Salinity Stress and Its Coping Strategies

Abstract

Maize is a cross-pollinated, polymorphic plant in nature. It is commonly a moderately salt-sensitive crop. Salinity stress is the main abiotic factor that arrests the physiological characteristics and plant growth of a maize plant. It causes the osmotic effect, associated with an increase in phytotoxic ions, oxidative stress by increased reactive oxygen species (ROS) production, and ionic effect in the cytosol. These salinity effects hinder the maize plant’s physiological processes such as respiration, photosynthesis, transpiration, stomatal functioning, hormone regulation, and functioning, seed germination, and dormancy and water relation with plants and ultimately reduce the plant growth and yield. However, the physiology of maize subjected to salinity shows various responses that depend on the genetic responses and growth stages. Maize plant undergoes many physiological changes and adapts some mechanism internally to cope with salinity stress. Numerous mitigating strategies such as application of chemicals, application of plant growth-promoting rhizobacteria (PGPR), application of hormones, and use of genetic and molecular techniques are used to handle salinity. This chapter will cover the effect of salinity on maize growth, its physiology, and physiological adaptations of maize plants with management strategies.

Effects of Abiotic Stress on Soil Microbiome

“…Salinity may be caused by the use of sewage sludge and manure, as well as municipal garden waste products resulting in salt accumulation in soil when frequently applied [140]. Due to high osmotic pressures as well as harmful ions and imbalance in nutrition [141], salinity causes suboptimal plant development and reduces activity of soil microbes. This is attributed to the fact that salinity changes water relation of plant tissues, nutrition and ion imbalance, and toxicity owing to the accumulation of Cland Na + ion levels in the plant tissues and soil [142][143][144][145].…”

Effect of Salinity Stress on Various Growth and Physiological Attributes of Two Contrasting Maize Genotypes

“…During the germination under salt stress, the seeds require a higher amount of water uptake due to the accumulation of the soluble solutes around the seeds which cause an increase in osmotic pressure [22]. This results in extreme uptake of the ions which cause ion toxicity in the plant reduced the water potential gradient between external environments and the seed inhibits the primary root emergence [23].…”

Effects of Compost Amendment on Glycophyte and Halophyte Crops Grown on Saline Soils: Isolation and Characterization of Rhizobacteria with Plant Growth Promoting Features and High Salt Resistance

“…In particular, maize plants could not tolerate the saline concentrations reached by the soil irrigated with the solution 300 mM NaCl (around 21 dS m −1 mean value, Table 2), confirming that maize, being a glycophyte plant, was the most sensitive one among those tested. The effects of salt stress on crop growth, and especially in the case of maize, are mainly due to high osmotic imbalance caused by low external water potential, ion toxicity induced by Na + and/or Cl − , photosynthesis inhibition, but also by an altered nutrition status which determines a reduction of essential element up-take [29]. Moreover, the presence of high level of these two ions in the plant tissues affects cellular and organelle membranes, primarily due to production of reactive oxygen species (ROS), limiting the plant growth and causing evident signs of phenotypic alterations before mortality, as we observed in the case of maize treated with 300 mM NaCl.…”