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The effects of root cooling and excision treatments on the growth of primary leaves of Phaseolus vulgar is L.
Author(s) -
SMITH P. G.,
DALE J. E.
Publication year - 1988
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1988.tb00265.x
Subject(s) - abscisic acid , phaseolus , petiole (insect anatomy) , seedling , botany , horticulture , fluridone , chemistry , biology , biochemistry , gene , hymenoptera
SUMMARY Seedlings of Phaseolus vulgaris L. were grown in nutrient solution at two temperatures and the free abscisic acid (ABA) content of primary leaves measured by radioimmunoassay with a monoclonal antibody (MAC‐62). Transfer of 7‐day‐old seedlings from solutions at 22.5 °C to 10 °C doubled the ABA content per g fresh weight after 6 h and led to a S‐fold increase by 24 h. Shorter incubations led to a 2.5‐fold rise 2 h after the start of cooling. Root‐cooling restricted leaf expansion rate but both the inhibition of leaf growth and the rise in ABA content were reversed when root temperature was returned to 22.5 °C. 2 h after transfer to control conditions half of the extra free ABA induced per leaf by root‐cooling was no longer present. Excision of seedling lateral roots impeded leaf expansion and led to enhanced ABA content after 24 h. Petiole ringing experiments showed that the rapid rise in ABA was not due to blockage of export from the leaves of root‐cooled plants, although export may have contributed to the fall in ABA when cooled seedlings were returned to 22.5 °C.