Macpherson Neil, Takeda Seiji, Shang Zhonglin, Dark Adeeba, Mortimer Jennifer C, Brownlee Colin, Dolan Liam, Davies Julia M
Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK.
Planta. 2008 May;227(6):1415-8. doi: 10.1007/s00425-008-0716-2. Epub 2008 Mar 4.
NADPH oxidase activity is involved in plant adaptation and development. The reactive oxygen species sourced by NADPH oxidase activity may contribute to wall strength and protoplast volume adjustment. Root hair bulge apices of the NADPH oxidase mutant rhd2/Atrbohc were more robust than the kjk cellulose synthase mutant, but burst more readily than the wild type (WT). Root epidermal wall appeared impaired in rhd2/Atrbohc, as revealed by the number of protoplasts released by wall-degrading enzymes. Root hair bulges of rhd2/Atrbohc burst more than the WT when challenged in situ with hypo-osmotic low ionic strength medium. Inhibition of NADPH oxidase activity with diphenylene iodonium caused WT to phenocopy the rhd2/Atrbohc bursting in response to hypo-osmotic shock. This implicates RHD2/AtRBOHC in softening the cell wall to permit protoplast expansion. Overall, the results point to a role for RHD2/AtRBOHC in contributing to wall strength.
NADPH氧化酶活性参与植物的适应和发育过程。由NADPH氧化酶活性产生的活性氧可能有助于细胞壁强度和原生质体体积的调节。NADPH氧化酶突变体rhd2/Atrbohc的根毛突出顶端比kjk纤维素合酶突变体更粗壮，但比野生型更容易破裂。如通过细胞壁降解酶释放的原生质体数量所显示，rhd2/Atrbohc的根表皮壁似乎受损。当在原位用低渗低离子强度培养基进行挑战时，rhd2/Atrbohc的根毛突出比野生型更容易破裂。用二苯碘鎓抑制NADPH氧化酶活性会使野生型在低渗休克反应中表现出与rhd2/Atrbohc破裂相似的表型。这表明RHD2/AtRBOHC在软化细胞壁以允许原生质体扩张方面发挥作用。总体而言，结果表明RHD2/AtRBOHC在增强细胞壁强度方面发挥作用。
