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Phosphatidylinositol 4,5‐bisphosphate is important for stomatal opening
Author(s) -
Lee Yuree,
Kim YongWoo,
Jeon Byeon Wook,
Park KiYoub,
Suh Su Jeoung,
Seo Jiyoung,
Kwak June M.,
Martinoia Enrico,
Hwang Inhwan,
Lee Youngsook
Publication year - 2007
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/j.1365-313x.2007.03277.x
Subject(s) - guard cell , phosphatidylinositol 4,5 bisphosphate , phosphatidylinositol , arabidopsis , mutant , inositol , microbiology and biotechnology , chemistry , cytosol , biophysics , biochemistry , biology , signal transduction , receptor , enzyme , gene
Summary Previously, we demonstrated that a protein that binds phosphatidylinositol 4,5‐bisphosphate [PtdIns(4,5)P 2 ] inhibits both light‐induced stomatal opening and ABA‐induced stomatal closing. The latter effect is due to a reduction in free PtdIns(4,5)P 2 , decreasing production of inositol 1,4,5‐trisphosphate and phosphatidic acid by phospholipases C and D. However, it is less clear how PtdIns(4,5)P 2 modulates stomatal opening. We found that in response to white light irradiation, the PtdIns(4,5)P 2 ‐binding domain GFP:PLCδ1PH translocated from the cytosol into the plasma membrane. This suggests that the level of PtdIns(4,5)P 2 increases at the plasma membrane upon illumination. Exogenously administered PtdIns(4,5)P 2 substituted for light stimuli, inducing stomatal opening and swelling of guard cell protoplasts. To identify PtdIns(4,5)P 2 targets we performed patch‐clamp experiments, and found that anion channel activity was inhibited by PtdIns(4,5)P 2 . Genetic analyses using an Arabidopsis PIP5K4 mutant further supported the role of PtdIns(4,5)P 2 in stomatal opening. The reduced stomatal opening movements exhibited by a mutant of Arabidopsis PIP5K4 ( At3g56960 ) was countered by exogenous application of PtdIns(4,5)P 2 . The phenotype of reduced stomatal opening in the pip5k4 mutant was recovered in lines complemented with the full‐length PIP5K4 . Together, these data suggest that PIP5K4 produces PtdIns(4,5)P 2 in irradiated guard cells, inhibiting anion channels to allow full stomatal opening.