Salinity and High Temperature Tolerance in Mungbean [Vigna radiata (L.) Wilczek] from a Physiological Perspective

Abstract

Biotic and abiotic constraints seriously affect the productivity of agriculture worldwide. The broadly recognized benefits of legumes in cropping systems—biological nitrogen fixation, improving soil fertility and broadening cereal-based agro-ecologies, are desirable now more than ever. Legume production is affected by hostile environments, especially soil salinity and high temperatures (HTs). Among legumes, mungbean has acceptable intrinsic tolerance mechanisms, but many agro-physiological characteristics of the Vigna species remain to be explored. Mungbean has a distinct advantage of being short-duration and can grow in wide range of soils and environments (as mono or relay legume). This review focuses on salinity and HT stresses on mungbean grown as a fallow crop (mungbean-rice-wheat to replace fallow-rice-wheat) and/or a relay crop in cereal cropping systems. Salinity tolerance comprises multifaceted responses at the molecular, physiological and plant canopy levels. In HTs, adaptation of physiological and biochemical processes gradually may lead to improvement of heat tolerance in plants. At the field level, managing or manipulating cultural practices can mitigate adverse effects of salinity and HT. Greater understanding of physiological and biochemical mechanisms regulating these two stresses will contribute to an evolving profile of the genes, proteins, and metabolites responsible for mungbean survival. We focus on abiotic stresses in legumes in general and mungbean in particular, and highlight gaps that need to be bridged through future mungbean research. Recent findings largely from physiological and biochemical fronts are examined, along with a few agronomic and farm-based management strategies to mitigate stress under field conditions.

The effects of humic acid on growth and ion uptake of mung bean (Vigna radiata (L.) Wilczek) grown under salt stress

“…It is well known that salinity has a drastic effect on general plant growth through osmotic stress and ion toxicity (Grattan and Grieve, 1998;Munns, 2002;Hanumantha et al, 2016), and causes a decline in the rates of net photosynthesis and decrease in nutrient uptake (Parida and Das, 2005;Cha-Um and Kirdmanee, 2009). …”

“…Salinity may also cause a reduction in rhizobial nodulation directly or indirectly in legumes (Hanumantha et al, 2016) resulting in reduced N accumulation (Alam, 1994;Turan et al, 2007 a,b).…”

Physiological and Biochemical Analyses of Sorghum Varieties Reveal Differential Responses to Salinity Stress

“…Germination is one of the most critical periods for a crop subjected to salinity. Higher salt stress retards seed germination and root emergence and leads to poor crop establishment which is deleterious and prevents the plant in maintaining their proper nutritional requirements necessary for their healthy growth [3]. Reduced germination is the consequence of either direct toxic effect of salt or the general delay of the germination process caused by osmotic stress [4].…”

Seed treatment with nano‐iron (III) oxide enhances germination, seeding growth and salinity tolerance of sorghum

“…In general, sorghum is considered as moderately tolerant to soil salinity (Igartua, Gracia, & Lasa, 1995); however, it is susceptible to salinity at seedling and reproductive stages (Kafi, Jafari, & Moayedi, 2013). Salinity stress affects plants in many ways through ion toxicity, nutritional disorder, oxidative stress, water stress, alteration in metabolic processes, leading to reduced growth, development and survival (Chinnusamy, Jagendorf, & Zhu, 2005;Hanumantha-Rao, Nair, & Nayyar, 2016;Munns, 2002). Therefore, development of crop management techniques for enhancing sorghum soil salinity is critically important.…”