Osmotic stress decreases PIP aquaporin transcripts in barley roots but H2O2 is not involved in this process

Maki Katsuhara, Nobuya Tsuji, Mineo Shibasaka, Sanjib Kumar Panda

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Previous reports indicate that salt stress reduces the root hydraulic conductance and the expression of plasmamembrane-type aquaporins (PIPs). As a molecular mechanism for this phenomenon, the present study found evidence that the osmotic component, but probably not an ion-specific component, decreases PIP transcripts. Eight of ten PIP transcripts were reduced to less than half by 360 mM mannitol treatment for 12 h in comparison with control samples. A large decrease of HvPIP2;1 protein was also recorded. This reduction of both transcripts and proteins of HvPIP2s should be physiologically effective for preventing or reducing dehydration at an initial phase of severe salt/osmotic stress. Root cell sap osmolality increased from 278 to 372 mOsm 24 h after 360 mM mannitol treatment. These steps can secure survival and growth recovery with water reabsorption in barley. Our data also suggest that H2O2 seems not to be the main cause of osmotic stress-induced transcriptional down-regulation within the concentrations (20–500 μM) and time periods (24 h) examined, although H2O2 was previously proposed to be involved in the mechanisms of salinity/osmotic tolerance.

Original languageEnglish
Pages (from-to)787-792
Number of pages6
JournalJournal of Plant Research
Volume127
Issue number6
DOIs
Publication statusPublished - Oct 30 2014

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Keywords

  • Barley
  • HO
  • Osmotic stress
  • PIP aquaporin
  • Salt stress

ASJC Scopus subject areas

  • Plant Science
  • Medicine(all)

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