Physiological and biochemical changes during the loss of desiccation tolerance in germinating Adenanthera pavonina L. seeds.

EDUARDO E.L. BORGES,GIULIANA C.M. SOARES,JOSÉ M.R. FARIA,DENISE C.F.S. DIAS

doi:10.1590/0001-3765201520140195

EDUARDO E.L. BORGES, GIULIANA C.M. SOARES + Show 2 more

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https://doi.org/10.1590/0001-3765201520140195

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Abstract

We investigated the loss of desiccation tolerance (DT) in Adenanthera pavonina seeds during germination. Seeds were subjected to imbibition for 0, 24, 36, 48, 60 and 81 h, then dried to their initial moisture content (13%), rehydrated and evaluated for survival (resumption of growth and development of normal seedlings) and membrane system integrity (electrolyte leakage). Embryonic axes of seeds subjected only to imbibition during the same early time periods were used to investigate the electrophoretic patterns of heat-stable proteins and the relative nuclear DNA content. In A. pavonina seeds, DT remained unchanged until 36 h of imbibition (resulting in germination and 82% normal seedlings), after which it was progressively lost, and seeds with a protruded radicle length of 1 mm did not withstand dehydration. The loss of desiccation tolerance could not be related to either membrane damage caused by drying or the resumption of the cell cycle during germination. However, the decrease in heat-stable protein contents observed throughout germination may be related to the loss of DT in A. pavonina seeds.

Highlights

Desiccation tolerance can be defined as the capacity of seeds to survive and maintain their physiological activities when subjected to a rigorous drying process
The objective of this study was to investigate whether the loss of desiccation tolerance is associated with the membrane damage caused by drying, with the activation of the cell cycle, or with the levels of heat-stable proteins during germination
Different imbibition times were selected to evaluate the loss of desiccation tolerance (DT) during germination: 0, 24, 36, 48, 60 and 81 h of imbibition

Summary

Introduction

Desiccation tolerance can be defined as the capacity of seeds to survive and maintain their physiological activities when subjected to a rigorous drying process. To prevent or minimize the damage caused by desiccation in orthodox seeds, a series of repair mechanisms are activated, the regulation of which is highly complex (Farrant and Moore 2011, Maia et al 2011, Gechev et al 2012, Dinakar and Bartels 2013). Among these mechanisms, the synthesis of protective molecules, such as heat shock proteins

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