Moringa leaf extract improves biochemical attributes, yield and grain quality of rice (Oryza sativa L.) under drought stress.

Shahbaz Khan,Abdul Basit,Zuhair Hasnain,Muhammad Bilal Hafeez,Muhammad Mudassar Maqbool,Shahid Farooq,Bandar S Aljuaid,Safdar Bashir,Yunzhou Li,Saqib Bashir,Muhammad Sohail Saddiq,Ahmed M El-Shehawi,Sohail Irshad

doi:10.1371/journal.pone.0254452

Abstract

Changing climate, food shortage, water scarcity and rapidly increasing population are some of the emerging challenges globally. Drought stress is the most devastating threat for agricultural productivity. Natural plant growth substances are intensively used to improve the productivity of crop plants grown under stressed and benign environments. The current study evaluated whether leaf extract of different moringa (Moringa oleifera L.) could play a role in improving drought-tolerance of rice (Oryza sativa L.). Rice plants were grown under three drought conditions, i.e., no, moderate and severe drought (100, 75 and 50% field capacity, respectively). Moringa leaf extract (MLE) obtained from four landraces (Multan, Faisalabad, D. G. Khan and exotic landrace from India) was applied during critical crop growth stages, i.e., tillering, panicle initiation and grain filling. Drought stress adversely affected the gas exchange attributes, photosynthetic pigments, antioxidant enzymes’ activities, yield and quality parameters of rice. Application of MLE from all landraces significantly improved physiological, biochemical and yield parameters under stressed and normal environmental conditions. The highest improvement in gas exchange traits (photosynthetic rate, stomatal conductance and respiration rate), photosynthetic pigments (chlorophyll a, b and carotenoids) and enzymatic activities (superoxide dismutase, catalase) and oxidative marker (H2O2) was recorded with MLE obtained from Faisalabad landrace. The application of MLE of Faisalabad landrace also improved yield and grain quality of rice grown under drought stress as well as drought-free environment. Thus, MLE of Faisalabad can be successfully used to improve growth, productivity and grain quality of rice under drought stress.

Highlights

Changing climate, food shortage, water scarcity and rapidly increasing population are some of emerging challenges globally faced by the agricultural community
The highest A, gs and E were observed maximum under CC followed by moderate drought stress (MDS), while severe drought stress (SDS) recorded the lowest values of these physiological parameters
The highest A was recorded for Moringa leaf extract (MLE)-LF, which was similar to MLE D. G. Khan landrace (MLE-LD) and MLE-LM

Summary

Introduction

Food shortage, water scarcity and rapidly increasing population are some of emerging challenges globally faced by the agricultural community. Drought stress is the most devastating threat for agricultural productivity [1]. Roots of rice seedling are very sensitive to abiotic stresses because they inhibit the cell expansion and other attributes of root development system [5]. Enzymatic antioxidants such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and non-enzymatic antioxidants play a vital role in detoxifying ROS [6]. Drought stress is very harmful at reproductive and grain-filling stages as it affects pollination, causes male sterility and decreases grain formation in rice. Drought stress decreases grain-filling rate and duration, grain weight and grain yield [7]

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Results

Discussion

Conclusion