Exogenously Applied Nitric Oxide Enhances Salt Tolerance in Rice (Oryza sativa L.) at Seedling Stage

Teferi Adamu,Adil Hussain,Bong-Gyu Mun,Byung-Wook Yun,Sang-Uk Lee

doi:10.3390/agronomy8120276

Teferi Adamu, Adil Hussain + Show 3 more

Open Access

https://doi.org/10.3390/agronomy8120276

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Abstract

Salinity is one of the major abiotic factors that limit rice production worldwide. Previous trends show that salt concentration in rivers is increasing consistently, posing potentially adverse threats in the near future. Thus, crops currently being cultivated, particularly in small-scale farming systems, are under high threat from salinity. In this study, we investigated the mitigating effect of nitric oxide (NO) on salt stress in rice based on the assessment of changes in the transcript levels of different genes and the phenotypic response of rice genotypes. We observed that exogenously applied NO increased the expression levels of OsHIPP38, OsGR1, and OsP5CS2 in the susceptible genotype of rice, whereas in the tolerant genotype, the effect of NO was mainly in counteracting the salt-induced gene expression that diverts cellular energy for defense. Moreover, seedlings that were pretreated with NO showed high biomass production under salt stress conditions, indicating the positive role of NO against salt-induced leaf chlorosis and early senescence. The effect of NO-mediated enhancement was more pronounced in the salt tolerant genotype. Therefore, the use of NO with the integration of tolerant genes or genotypes will enhance salt tolerance levels in rice.

Highlights

Rice is a major cereal crop grown globally and is of principal importance as a staple food source for more than half of the world population [1]
The results showed that application of nitric oxide (NO) together with salt stress was not found important to seedlings and because of this, pretreatment application was used (Figure S2 and S3)
The results showed that the transcript accumulations and expression patterns of OsHIPP38 were different over time in all genotypes (Figure 1)

Summary

Introduction

Rice is a major cereal crop grown globally and is of principal importance as a staple food source for more than half of the world population [1]. World rice production is projected to be 915 million tons by 2050, which is far less than that expected based on the yield doubling hypothesis to supply for the global food demand [2,3]. In Asia alone, where more than 90% of the world’s rice production is harvested, 21.5 million ha of agricultural land is affected by salt stress [12]. For this reason, the large area of irrigated lands became fallow

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