Premium
PIN6 is required for nectary auxin response and short stamen development
Author(s) -
Bender Ricci L.,
Fekete Megan L.,
Klinkenberg Peter M.,
Hampton Marshall,
Bauer Brittany,
Malecha Matthew,
Lindgren Khrystyne,
A. Maki Jennifer,
Perera M. Ann D. N.,
Nikolau Basil J.,
Carter Clay J.
Publication year - 2013
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12184
Subject(s) - auxin , nectar , mutant , biology , myb , wild type , microbiology and biotechnology , stamen , transcription factor , polar auxin transport , botany , arabidopsis , gene , genetics , pollen
Summary The PIN family of proteins is best known for its involvement in polar auxin transport and tropic responses. PIN 6 (At1g77110) is one of the remaining PIN family members in A rabidopsis thaliana to which a biological function has not yet been ascribed. Here we report that PIN 6 is a nectary‐enriched gene whose expression level is positively correlated with total nectar production in A rabidopsis, and whose function is required for the proper development of short stamens. PIN 6 accumulates in internal membranes consistent with the ER , and multiple lines of evidence demonstrate that PIN 6 is required for auxin‐dependent responses in nectaries. Wild‐type plants expressing auxin‐responsive DR 5: GFP or DR 5: GUS reporters displayed intense signal in lateral nectaries, but pin6 lateral nectaries showed little or no signal for these reporters. Further, exogenous auxin treatment increased nectar production more than tenfold in wild‐type plants, but nectar production was not increased in pin6 mutants when treated with auxin. Conversely, the auxin transport inhibitor N –1–naphthylphthalamic acid ( NPA ) reduced nectar production in wild‐type plants by more than twofold, but had no significant effect on pin6 lines. Interestingly, a MYB 57 transcription factor mutant, myb57–2 , closely phenocopied the loss‐of‐function mutant pin6–2 . However, PIN 6 expression was not dependent on MYB 57 , and RNA ‐seq analyses of pin6–2 and myb57–2 mutant nectaries showed little overlap in terms of differentially expressed genes. Cumulatively, these results demonstrate that PIN 6 is required for proper auxin response and nectary function in Arabidopsis. These results also identify auxin as an important factor in the regulation of nectar production, and implicate short stamens in the maturation of lateral nectaries.