Salinity decreases transpiration of sorghum plants

Miguel Julio Machado Guimarães,Juliane Rafaele Alves Barros,Lilia Gomes Willadino,Welson Lima Simões,Richard Erickson

doi:10.1017/exp.2020.22

Abstract

AbstractGrowing in a saline environment causes changes in important physiological processes that are directly related to plant growth and development. In this study we evaluated the effect of salinity on transpiration of sorghum plants in semi-arid conditions and found that the highest rates of transpiration were observed in the hottest hours of the day, between 10 a.m. and 3 p.m., with plants subjected to the saline environment having their transpiration reduced by up to 70% when compared to the non-saline environment. This behavior can be reflected in reductions in plant growth and development due to reduced water absorption by the roots, consequently causing an imbalance of nutrients in the plant due to low absorption rate and competition between nutrients and salts in the preferred routes of absorption in the roots.

Highlights

Salinity is one of the most severe environmental stresses and the responses given by plants are diverse
There was a linear reduction of the total leaf area of the plants with an increase in the salinity of the water used for irrigation, which contributed to lower perspiration values of the plants submitted to the higher salinity levels
It was observed that specific transpiration decreased with the increase in salinity (Fig. 1), evidencing the effect of salts on the gas exchange of sorghum plants

Summary

Introduction

Salinity is one of the most severe environmental stresses and the responses given by plants are diverse These are reflected in physiological variables (stomach conductance, rate of perspiration and photosynthesis) (Freire et al, 2014), biometrics (height, leaf area, biomass production) (Guimarães et al, 2019), biochemistry (antioxidant enzymes) (Barbosa et al, 2014). Sorghum bicolor (L.) Moench is a crop species that presents C4 mechanism, and is one of the most versatile and efficient species in terms of photosynthetic mechanism (Berenguer & Faci, 2001). This contributes to its greater resistance to adverse conditions. Theses mechanisms have different energy costs for the plants, which negatively affect plant gas exchange, and plant growth and development (Hassanein et al, 2010)

Results

Findings

Conclusions