Casati Paula, Stapleton Ann E, Blum James E, Walbot Virginia
Department of Biological Sciences, Stanford University, 385 Serra Mall, Stanford, CA 94305-5020, USA.
Plant J. 2006 May;46(4):613-27. doi: 10.1111/j.1365-313X.2006.02721.x.
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 2,000 to 3,400 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 high-altitude 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.
通过对玉米进行表达谱分析，开展了一项比较分析，以鉴定玉米对UV - B响应机制中的新成分。在2000至3400米自然生长的五个高海拔地方品种，比低海拔且纬度相近地区的植物接受更高的UV - B通量。这些高海拔地方品种直接与一个低海拔品系以及其他温带玉米品系的文献报道进行了比较。微阵列分析表明，在UV - B响应转录本中，几种与染色质重塑相关的基因在高海拔品系中UV - B处理前后差异表达。通过测量叶拱、叶黄化和坏死增加以及所选基因的UV - B调节改变，四个此类与染色质相关基因表达较低的RNAi转基因植物对UV - B表现出超敏反应。这些结果共同表明，参与染色质重塑的基因对UV - B适应至关重要，并且一些高海拔品系表现出对这一挑战的适应性。
