Germination and antioxidant action in melon seeds exposed to salt stress

Daniel Teixeira Pinheiro,Aparecida Leonir Da Silva,Laércio Junio Da Silva,Marcelo Coelho Sekita,Denise Cunha Fernandes Dos Santos Dias

doi:10.1590/1983-40632016v4640431

Daniel Teixeira Pinheiro, Aparecida Leonir Da Silva + Show 3 more

Open Access

https://doi.org/10.1590/1983-40632016v4640431

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Abstract

ABSTRACT Salinity influences all germination stages and may adversely affect the seedlings establishment in the field. This study aimed at assessing the effects of salt stress on the physiological potential of melon (Cucumis melo L.) seeds. Germination and activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) enzymes were assessed at the osmotic potentials of 0.0 MPa, -0.1 MPa, -0.2 MPa, -0.3 MPa, -0.4 MPa and -0.5 MPa. The enzymatic activity was assessed after 24 h, 48 h and 72 h of imbibition. Seed germination was zero at -0.5 MPa and 91 % and 85 % at -0.1 MPa and -0.2 MPa, respectively. In general, the activity of SOD, CAT and POX enzymes increased with the salt-induced stress, in the different times of imbibition, and these increases were more evident at -0.4 MPa and -0.5 MPa. The salt stress induced by NaCl diminishes the germination rate of melon seeds, particularly from the osmotic potential of -0.2 MPa. There is a significant increase in the activity of SOD, CAT and POX enzymes, mainly after 48 h of exposure.

Highlights

Germination starts when the seed absorbs water and culminates in several cellular processes that will allow the embryo to grow and develop (Marcos-Filho 2015)
This study aimed at assessing the effects of salt stress on the physiological quality and antioxidant enzymes activity in melon seeds
In the first germination count (Figure 1a) and in germination (Figure 1b), the seeds that were subjected to the osmotic potential of -0.4 MPa exhibited reductions of approximately 90 percentage points (p.p.), if compared to the control (0.0 MPa)

Summary

Introduction

Germination starts when the seed absorbs water and culminates in several cellular processes that will allow the embryo to grow and develop (Marcos-Filho 2015). This process involves complex cellular changes, among them protein hydration, increased respiration, macromolecule synthesis and cell elongation (Bewley et al 2013). It is considered a fundamental and vital stage of the plants growth, determining the crop establishment and yield in the field (Hasanuzzaman et al 2013). Ion toxicity, during the germination process, causes diverse physiological and biochemical disorders, such as hormonal imbalance and reduced use of reserves (Yacoubi et al 2013)

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