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Hormone interactions and regulation of PsPK2::GUS compared with DR5::GUS and PID::GUS in Arabidopsis thaliana
Author(s) -
Bai Fang,
DeMason Darleen A.
Publication year - 2008
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.3732/ajb.95.2.133
Subject(s) - auxin , cytokinin , gibberellin , arabidopsis , biology , arabidopsis thaliana , shoot , gus reporter system , gibberellic acid , botany , plant hormone , reporter gene , gene expression , gene , biochemistry , mutant , germination
The putative pea PINOID homolog, PsPK2 , is expressed in all growing plant parts and is positively regulated by auxin, gibberellin, and cytokinin. Here, we studied hormonal regulation of PsPK2::GUS expression compared with DR5::GUS and PID::GUS in Arabidopsis . PsPK2::GUS, DR5::GUS , and PID::GUS expression in Arabidopsis shoots is mainly localized in the stipules, hydathodes, veins, developing leaves, and cotyledons. Unlike DR5::GUS, PsPK2::GUS , and PID::GUS are weakly expressed in root tips. Both DR5::GUS and PsPK2::GUS are induced by different auxins and are more sensitive to methyl indole acetic acid, 4‐chloro‐indole acetic acid, and α‐naphthalene acetic acid than others. GA 3 has no significant effect on GUS activity in DR5::GUS ‐transformed seedlings compared to the control, but induction by auxin and gibberellin in combination is synergistic. Cytokinin increases auxin transport in Arabidopsis seedlings. Auxin, gibberellin, and cytokinin all increase GUS activity in shoots of PsPK2::GUS transformed plants compared to the control. However, only auxin and gibberellin increase GUS activity in PID::GUS shoots. In conclusion, auxin, gibberellin, and cytokinin positively regulate PsPK2 expression in shoots, but not in roots. Auxin and gibberellin also upregulate AtPIN1 and LEAFY expression, which is similar to PsPIN1 and Uni in pea. With minor exceptions, the orthologous genes from both species are regulated similarly.