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Differential responses of plasma membrane aquaporins in mediating water transport of cucumber seedlings under osmotic and salt stresses
Author(s) -
QIAN ZHENGJIANG,
SONG JUANJUAN,
CHAUMONT FRANÇOIS,
YE QING
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12319
Subject(s) - aquaporin , peg ratio , osmotic shock , osmosis , water transport , polyethylene glycol , hydraulic conductivity , salinity , membrane , chemistry , osmoregulation , biophysics , osmotic pressure , gene isoform , microbiology and biotechnology , biology , biochemistry , water flow , soil water , gene , ecology , finance , environmental engineering , engineering , economics
It has long been recognized that inhibition of plant water transport by either osmotic stress or salinity is mediated by aquaporins ( AQPs ), but the function and regulation of AQPs are highly variable among distinct isoforms and across different species. In this study, cucumber seedlings were subjected to polyethylene glycol ( PEG ) or NaCl stress for duration of 2 h or 24 h. The 2 h treatment with PEG or NaCl had non‐significant effect on the expression of plasma membrane AQP ( CsPIPs ) in roots, indicating the decrease in hydraulic conductivity of roots ( Lp r ) and root cells ( Lp rc ) measured in these conditions were due to changes in AQP activity. After both 2 h and 24 h PEG or NaCl exposure, the decrease in hydraulic conductivity of leaves ( K leaf ) and leaf cells ( Lp lc ) could be attributed to a down‐regulation of the two most highly expressed isoforms, CsPIP 1;2 and CsPIP 2;4 . In roots, both Lp r and Lp rc were further reduced after 24 h PEG exposure, but partially recovered after 24 h NaCl treatment, which were consistent with changes in the expression of CsPIP genes. Overall, the results demonstrated differential responses of CsPIPs in mediating water transport of cucumber seedlings, and the regulatory mechanisms differed according to applied stresses, stress durations and specific organs.