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Sequence of drought response of maize seedlings in drying soil
Author(s) -
Schmidhalter Urs,
Evéquoz Michel,
Camp KarlHeinz,
Studer Christoph
Publication year - 1998
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 - 10.1034/j.1399-3054.1998.1040203.x
Subject(s) - elongation , transpiration , biology , turgor pressure , agronomy , zea mays , soil water , poaceae , horticulture , botany , photosynthesis , ecology , materials science , metallurgy , ultimate tensile strength
Leaf elongation in monocotyledonous plants is sensitive to drought. To better understand the sequence of events in plants subjected to soil drying, leaf elongation and transpiration of maize seedlings ( Zea mays L.) of 4 cultivars were monitored continuously and the diurnal courses of the root and leaf water relations were determined. Results from this study indicate the following sequence of drought response: Leaf elongation decreased before changes in the leaf water relations of non‐growing zones of leaf blades were detected and before transpiration decreased. Reductions in leaf elongation preceded changes in the root water potential (ψ w ). Root ψ w was not a very sensitive indicator of soil dryness, whereas the root osmotic potential (ψ s ) and root turgor (ψ p ) were more sensitive indicators. The earliest events observed in drying soil were a significant increase in the largest root diameter class (1 720 to 1 960 gm) and a decrease in leaf elongation ( P = 0.08) 2 days after withholding water. Significant increases in root length were observed 2 days later. Soil drying increased the number of fine roots with diameters of <240 µm. Slight increases in soil strength did not affect leaf elongation in the drying soil.