The roles and interactions of ethylene with gibberellins in the far-red enriched light-mediated growth of Solanum lycopersicum seedlings |
| |
Authors: | Leonid V. Kurepin Wing-Kin Yip Rong Fan Edward C. Yeung David M. Reid |
| |
Affiliation: | (1) Department of Biological Sciences, University of Calgary, University Drive 2500 NW, Calgary, AB, T2N 1N4, Canada;(2) Department of Botany, The University of Hong Kong, Hong Kong SAR, China |
| |
Abstract: | Wild type (WT) tomato seedlings responded to a low red to far-red (R/FR) ratio with increased stem elongation, similar leaflet area expansion and lower shoot ethylene levels. The levels of endogenous growth-active GA1 and its immediate precursor GA20 were decreased by low R/FR ratio, whereas the levels of GA1 catabolite, GA8, increased. To examine the interaction of ethylene with GAs in regulating tomato shoot growth under low R/FR ratio, transgenic (T) seedlings bearing Le-ACS2 and Le-ACS4 antisense mRNA were utilized. Low R/FR ratio increased stem elongation and decreased ethylene levels in T tomato shoots, as it did in WT shoots. However, T stems were significantly taller than the WT stems under low R/FR ratio. Leaflet areas were significantly larger for T, than WT seedlings under both R/FR ratios. Low R/FR ratio did not decrease endogenous levels of GA1 and GA20 in T shoots, but did increase GA8 levels, which were higher than in WT shoots. These results, and hormone/inhibitor application studies, showed that in tomato shoots subjected to low R/FR ratio, GAs play a growth-promotive role in stem elongation, whereas ethylene is growth-inhibitory. Further, these results may imply that decreasing ethylene production under low R/FR ratio causes increases in stem elongation and GA levels. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|