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Effects of Moderate Water Deficit (Stress) on Wheat Seedling Growth and Plastid Pigment Development
Author(s) -
DUYSEN MURRAY E.,
FREEMAN THOMAS P.
Publication year - 1974
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1974.tb03702.x
Subject(s) - etiolation , seedling , chlorophyll , osmotic shock , carotenoid , pigment , greening , chlorophyll a , botany , plastid , biology , osmotic pressure , photosynthetic pigment , chlorophyll b , horticulture , absorbance , chloroplast , chemistry , biochemistry , ecology , organic chemistry , gene , enzyme , chromatography
Etiolated 6‐day‐old wheat ( Triticum aestivum L. cv. Chris) seedlings were subjected to osmotic stress by an application of polyethylene glycol 12 h prior to the exposure to a continuous 72‐h light period. The water potential of the primary leaf of stressed seedlings was between –9 and –14 bars throughout the light period. Stress impaired seedling growth, leaf unfolding, and the increase in leaf area. The imposed osmotic stress reduced total chlorophyll accumulation, particularly after 9 h light, suggesting that this is the approximate time period for the depletion of the protochlorophyll(ide) pool and the pool of an essential protochlorophyll(ide) precursor. The chlorophyll a/b ratio of extracts from stressed and non‐stressed plants was the same during the 72‐h greening period. Water deficit stress impaired carotenoid accumulation sooner than the impairment of chlorophyll production suggesting either a smaller carotenoid pool size of precursors or that the metabolic pathway of carotenoid synthesis was more sensitive to stress. Shifts from the usual plastid pigment absorbance maxima were not observed in these studies.