Pellinen Riikka I, Korhonen Minna-Sisko, Tauriainen Airi A, Palva E Tapio, Kangasjärvi Jaakko
Institute of Biotechnology and Department of Biosciences, Division of Genetics, P.O. Box 56, FIN-00014 University of Helsinki, Finland.
Plant Physiol. 2002 Oct;130(2):549-60. doi: 10.1104/pp.003954.
The function of hydrogen peroxide (H(2)O(2)) as a signal molecule regulating gene expression and cell death induced by external stresses was studied in birch (Betula pendula). Ozone (O(3)), Pseudomonas syringae pv syringae (Pss), and wounding all induced cell death of various extents in birch leaves. This was temporally preceded and closely accompanied by H(2)O(2) accumulation at, and especially surrounding, the lesion sites. O(3) and Pss, along with an artificial H(2)O(2) producing system glucose (Glc)/Glc oxidase, elicited elevated mRNA levels corresponding to genes encoding reactive oxygen species detoxifying enzymes, Pal, Ypr10, and mitochondrial phosphate translocator 1. In addition to the regulation of gene expression, Glc/Glc oxidase also induced endogenous H(2)O(2) production in birch leaves, accompanied by cell death that resembled O(3) and Pss damage. Wound-induced gene expression differed from that induced by O(3) and Pss. Thus, it appears that at least two separate defense pathways can be activated in birch leaves by stress factors, even though the early H(2)O(2) accumulation response is common among them all.
研究了过氧化氢（H₂O₂）作为调节基因表达和外部胁迫诱导的细胞死亡的信号分子在白桦（Betula pendula）中的作用。臭氧（O₃）、丁香假单胞菌丁香致病变种（Pss）和创伤均能诱导白桦叶片不同程度的细胞死亡。在病变部位及其周围，H₂O₂积累在时间上先于细胞死亡并紧密伴随。O₃和Pss以及人工H₂O₂产生系统葡萄糖（Glc）/葡萄糖氧化酶，可使与编码活性氧解毒酶、苯丙氨酸解氨酶（Pal）、Ypr10和线粒体磷酸转运体1的基因相对应的mRNA水平升高。除了调节基因表达外，Glc/葡萄糖氧化酶还能诱导白桦叶片内源性H₂O₂的产生，并伴有类似于O₃和Pss损伤的细胞死亡。创伤诱导的基因表达与O₃和Pss诱导的不同。因此，尽管早期H₂O₂积累反应在所有胁迫因素中都很常见，但在白桦叶片中，至少有两条独立的防御途径可被胁迫因子激活。
