Overexpression of antisense phosphatase 2C affords cold resistance in hybrid Populus davidiana × Populus bolleana.

Abstract

Overexpression of the abiotic and biotic stress-resistance genes of the plant signaling pathway is well known for its significant role in the regulation of plant growth and enhancement of the productivity of agricultural land under changing climatic conditions. This research aimed to clone Populus davidiana × Populus bolleana PP2C (PdPP2C) gene and analyze its structure and function, and downregulate PdPP2C by overexpression of its antisense PdPP2C (AS-PdPP2C) gene for enhancing cold resistance in transgenic lines of hybrid P. davidiana × P. bolleana. PdPP2C was cloned and transformed to identify its function, and its antisense was overexpressed via downregulation to increase the cold resistance in transgenic lines of hybrid P. davidiana × P. bolleana. Antisense inhibition of protein phosphatase 2C accelerates the cold acclimation of Poplar (P. davidiana × P. bolleana) gene in terms of antifreeze. PdPP2C was expressed in the roots, stems, and leaves of P. davidiana × P. bolleana, and the expression was higher in the leaves. The expression of PdPP2C was also significantly downregulated at low-temperature (0°C and 4°C) stress. The relative conductivity and malondialdehyde content of non-transgenic lines were higher than those of AS-PdPP2C lines after 2days of cold treatment at - 1°C. The leaves of the transgenic lines were not wilted and showed no chlorosis compared with those of the non-transgenic lines. The AS-PdPP2C transgenic lines also showed higher freezing resistance than the non-transgenic lines. AS-PdPP2C participated in the regulation of freezing resistance.