Journal de gestion de la biodiversité et de foresterie

Wildfire Suppression Expenses were for Forest Service

Courtney

Several ABA transporters in different families have been reported in addition to the ABC transporter family. ABA transporters have been found in Arabidopsis NPF4.6, which was previously termed ABAImporting Transporter1 (AIT1), and numerous members of the Nitrate Transporter 1/Peptide Transporter Family (NPF) (using a modified yeast two-hybrid technique to screen arabidopsis cDNAs for proteins capable of generating connections between the ABA receptor PYR/PYL/RCAR and the PP2C protein phosphatase in yeast cells, NPF4.6 and related family members were successfully found. Overall, transport tests in insect cells expressing NPF4.6 revealed that this transporter is involved in the uptake of cellular ABA into cultured cells. NPF4.6 proteins coupled with fluorescent proteins were found primarily in the plasma membrane. NPF4.6 mutants showed less sensitivity to exogenously administered ABA during seed germination and early seedling growth than wild-type plants. Overexpression of NPF4.6, on the other hand, caused ABA hypersensitivity in seeds and during the early phases of development. The surface temperature of the inflorescence stems of npf4.6 mutants was lower than that of wild-type plants in adult plants. A promoter-reporter system was used to detect NPF4.6 promoter activity in imbibed seeds and vascular tissues of cotyledons, true leaves, hypocotyls, roots, and inflorescence stems. These findings imply that NPF4.6's role as an ABA importer in vascular areas influences stomata aperture regulation in shoots. Although NPF transporters have been functionally classified as nitrate transporte