AtNOA1 modulates nitric oxide accumulation and stomatal closure induced by salicylic acid in Arabidopsis.

Phytohormone salicylic acid (SA) has been documented to induce nitric oxide (NO) generation and stomatal closure in plants. However, the cellular components mediating these processes are limited. Here, we report that NO synthesis in guard cells and stomatal closure are markedly induced by SA in Arabidopsis wild type plants, whereas these effects caused by SA are suppressed significantly in noa1 T-DNA mutant plants. These results suggest that AtNOA1 regulates SA-triggered NO accumulation and stomatal closure in Arabidopsis.