Intercellular recognition and signal transduction in plants

本研究利用植物-微生物、生物激发子和物理刺激等多种系统，对细胞和组织-细胞的识别和信号转导进行了研究，主要结果如下：1）在Ca ^2+信号转导方面，Mg ^2+对Ca ^2+/H+逆向转运蛋白或Ca^2+的影响，证明了Ca^2+依赖性蛋白激酶的纯化和表征以及在激发子处理的悬浮培养细胞中Ca ^2+依赖性蛋白激酶参与肌醇磷脂周转和PAL诱导。2)N-乙酰壳寡糖引起水稻悬浮培养细胞的氧化爆发，产生OH自由基和各种蛋白质的磷酸化。3)通过物理刺激，在字符细胞中产生并转导活性电位，并通过肌球蛋白的Ca^2+依赖性磷酸化导致原生质流的停止。4)真菌诱导子刺激了氧化爆发，随后伴随着磷脂酶A的激活而发生脂质过氧化^[2]。马铃薯组织中的这种酶活性依赖于CaM和蛋白激酶，并且似乎是马铃薯糖蛋白。5)细胞骨架参与了植物细胞对入侵病原菌的排斥反应。6)在诱导大麦幼苗对病原菌的系统获得抗性中，发现感染或伤害信号首先引起电信号，然后产生一些分子作为次级信号。7)真菌诱导子处理的马铃薯组织中的氧化爆发依赖于Ca^<2+>内流、CaM和蛋白激酶，并通过产生H_2O_2引起亚系统的氧化爆发。全身下的氧化爆发也是由于Ca^<2+>信号传导。

In this research project, recognition and signal transduction in a cell as well as tissue-cells were investigated using various systems of plant-microbe, biotic elicitor or physical stimuli, and the following major results were obtained.1) In relation to Ca ^<2+>signalling, effect of Mg ^<2+>on the Ca ^<2+>/H+ antiporter or Ca^<2+>, purification and characterization of Ca^<2+>dependent protein kinase and involvement of Ca ^<2+>dependent protein kinase in inositol phospholipid turnover and PAL induction in elicitor-treated suspension cultured cells was demonstrated. 2) N-acetylchitoorigosaccharide elicited an oxidative burst generating OH radical and phosphorylation of the various proteins in rice suspension cultured cells. 3) Active electric potential was generated and transduced in characean cells by a physical stimulus and resulted in cause a cessation of protoplasmic streaming by Ca^<2+> dependent phosphorylation of myosin. 4) Fungal elicitors stimulated the oxidative burst, followed by lipid peroxidation with an activation of phospholipase A^2. This enzyme activity in potato tissues was dependent on CaM and protein kinase and appeared to be patatin. 5) Cytoskeleton was involved as some signal transduction in rejection-response of plant cells against invading pathogens. 6) In induction of systemic acquired resistance in barley seedlings to pathogens, infection or wounding signals was found to cause first a electric signal and then production of some molecules for secondary signal. 7) The oxidative burst in potato tissues treated with fungal elicitor was found to be dependent on Ca^<2+> influx, CaM and protein kinase and to cause a subsystemic oxidative burst by generated H_2O_2. The subsystemic oxidative burst was also due to Ca^<2+> signalling.