Vacuolar/pre-vacuolar compartment Qa-SNAREs VAM3/SYP22 and PEP12/SYP21 have interchangeable functions in Arabidopsis

作者：Uemura Tomohiro^*; Morita Miyo Terao; Ebine Kazuo; Okatani Yusuke; Yano Daisuke; Saito Chieko; Ueda Takashi; Nakano Akihiko

来源：Plant Journal, 2010, 64(5): 864-873.

DOI：10.1111/j.1365-313X.2010.04372.x

• SNARE
• vacuole
• pre-vacuolar compartment
• vacuolar transport
• Arabidopsis

P>SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptors) mediate specific membrane fusion between transport vesicles or organelles and target membranes. VAM3/SYP22 and PEP12/SYP21 are Qa-SNAREs that act in the vacuolar transport pathway of Arabidopsis thaliana, and are localized predominantly on the vacuolar membrane and the pre-vacuolar compartment (PVC), respectively. Previous studies have shown that loss-of-function mutants of VAM3/SYP22 or PEP12/SYP21 showed male gametophytic lethality, suggesting that VAM3/SYP22 and PEP12/SYP21 possess different, non-redundant functions. We have re-evaluated the effects of mutations in these genes using T-DNA insertion mutants in the Columbia accession. We found that a mutation in VAM3/SYP22 (vam3-1) caused pleiotropic abnormalities, including semi-dwarfism and wavy leaves. In contrast, a loss-of-function mutant of PEP12/SYP21 (pep12) showed no apparent abnormal phenotype. We also found that the double vam3-1 pep12 mutant had severely reduced fertilization competence, although male and female gametophytes (vam3-1-pep12-) maintained the ability to fertilize. Moreover, promoter swapping analysis revealed that expression of a GFP-PEP12/SYP21 fusion under the control of the VAM3/SYP22 promoter suppressed all phenotypes of the vam3-1 mutant. These results indicate that the functions of VAM3/SYP22 and PEP12/SYP21 were redundant and interchangeable.

• 出版日期2010-12