Authors: Sujuan Gao Xiuzhi Xie Songguang Yang Zhaoping Chen Xiaojing Wang
Publish Date: 2011/07/31
Volume: 39, Issue: 4, Pages: 4091-4100
Abstract
Deetiolation during seedling development is antagonistically regulated by blue light BL and gibberellins GAs The crosstalk between blue light BL and GA metabolism and signaling remains unclear Using the mutant har1 which is specifically hypersensitive to BL in deetiolation the involvement possibility of the GA metabolism GA signaling in the inhibition of mesocotyl elongation of the sorghum Sorghum bicolor L var R111 seeding under BL was investigated The inhibition of mesocotyl and cell elongation by BL was restored by application of exogenous GA3 in har1 The endogenous GA3 level correspondingly decreased in har1 mesocotyl especially from 1 to 4 h after BL irradiation Putative genes of GA metabolism enzymes SbGA20ox SbGA3ox and SbGA2ox were detected by RealTime PCR and the results showed that one of the SbGA2ox homologs appeared significantly higher transcript level in har1 than in R111 at 2 h after BL irradiation Putative homologous genes of DELLAs increased after BL irradiation and were higher in har1 among the three homologs Remarkable increase of the DELLA expression was observed responding to exogenous paclobutrazol PAC Our research provided evidence in monocot sorghum that the changes of a set of the GA metabolism and signaling genes might be involved in BLinduced inhibition of cell elongation
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