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Auxin‐induced cell expansion of potato tuber and chicory root: Role of hydroxyproline synthesis
Author(s) -
Shan P. R. M.,
Flood A. E.,
Wain R. L.
Publication year - 1984
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.1399-3054.1984.tb00371.x
Subject(s) - hydroxyproline , auxin , cell wall , biochemistry , chemistry , cichorium , gibberellic acid , biology , botany , gene , germination
We have reinvestigated the role of protein‐bound hydroxyproline (extensin) in auxininduced cell enlargement using discs excised from tubers of Solanum tuberosum L. cv. Pentland Crown and from roots of Cichorium intybus L. cv. Magdeburg. Extensin increases markedly in potato tuber discs treated with water and auxin, and the hydroxyproline is primarily in the cell wall. 2,2′‐Dipyridyl totally inhibits both hydroxyproline synthesis and auxin‐induced cell expansion in potato with the inhibitions being reversed in parallel by Fe 2+ . Free hydroxyproline also totally prevents induced cell enlargement. Pretreatment with gibberellic acid totally inhibits subsequent auxin‐induced cell expansion but does not inhibit hydroxyproline synthesis. Therefore, the level of hydroxyproline does not control auxin‐induced cell enlargement in potato tuber discs. Other interpretations are discussed but we conclude that extensin biosynthesis is necessary for auxin‐dependent cell expansion as inhibition of the synthesis prevents the induced expansion. Dipyridyl and free hydroxyproline partially inhibit auxin‐induced cell enlargement in chicory root discs. Thus a component of the auxin‐dependent cell enlargement in chicory is also dependent on extensin synthesis.