Effects of s 3307 e 1 4 chlorophenyl 4 4 dimethyl 2 1 2 4 triazol 1 yl 1 penten 3 ol an inhibitor of gibberellin biosynthesis on swelling of leaf sheath cells and on the arrangement of cortical microtubules in onion allium cepa cultivar senshu choko seedlings
Mita, T.; Shibaoka, H.
Plant and Cell Physiology 25(8): 1531-1540
1984
ISSN/ISBN: 0032-0781 Accession: 005323787
Treatment with S-3307, a newly developed growth retardant, caused swelling of leaf sheaths in 2- to 3-leafed young onion seedlings, which otherwise showed no swelling even under long-day conditions. Before swelling became evident, changes occurred in the arrangement of cortical microtubules in leaf sheath cells of S-3307-treated seedlings. Cortical microtubules in leaf sheath cells, which are normally oriented transversely to the cell axis in untreated seedlings, were oriented longitudinally or obliquely in treated seedlings. S-3307 exerted these effects only in seedlings grown under long-day conditions, but not under short-day conditions. Simultaneously applied GA reversed the effect of S-3307 on swelling, indicating that S-3307 acts as an inhibitor of GA biosynthesis in onion seedlings. Endogenous GA seems to play an important role in arranging cortical microtubules transversely to the cell axis.