“Genome-wide analysis of high altitude maize and gene knockdown stocks implicates chromatin remodeling proteins in responses to UV-B”

PAULA CASATI; ANN E STAPLETON; JAMES E BLUM; VIRGINIA WALBOT

Plant Journal

Año: 2006 vol. 46 p. 613 - 627

0960-7412

A comparative analysis, by expression profiling of maize, was performed to identify novel components in the mechanisms of maize responses to UV-B. Five high-altitude landraces grown from 2000 to 3400 m naturally receive higher UV-B fluence than plants at lower altitudes and similar latitudes. These high-altitude landraces were compared directly with a low-altitude line and with literature reports for other temperate maize lines. A microarray analysis demonstrated that among the UV-B responsive transcripts, several types of gene implicated in chromatin remodeling are differentially expressed before and after UV-B treatment in highaltitude lines. RNAi transgenic plants with lower expression of four such chromatin-associated genes exhibited hypersensitivity to UV-B by measurements of leaf arching, increased leaf chlorosis and necrosis, and altered UV-B regulation of selected genes. These results collectively suggest that genes involved in chromatin remodeling are crucial for UV-B acclimation and that some high-altitude lines exhibit adaptations to this challenge.