【作者】 葛才林； 万定珍； 丁艳； 商奇； 王泽港； 马飞； 罗时石；

【Author】 GE Cai-lin,WANG Ding-zhen,DING Yan,SHANG Qi,WANG Ze-gang,MA Fei,LUO Shi-shi (Key Laboratory of Crop Genetics and Physiolog of Jiangsu Province, Yangzhou University, Yangzhou, 225009,China)

【机构】 扬州大学江苏省作物遗传生理重点实验室；

【摘要】 本文应用同位素交换动力学和体外蛋白质磷酸化分析方法研究了1,2,4-三氯苯(TCB)和汞(Hg)胁迫对二个不同品种水稻幼苗体内Ca2+流动和蛋白质磷酸化的影响。结果显示,4~48h的Hg(0.1mmol·L-1)和TCB(5mg·L-1)处理提高叶片对Ca2+的吸收量,促进根系中吸收的Ca2+向叶片的运输。同位素交换动力学的分析表明,8h的Hg和TCB处理促使定位于细胞质膜上的Ca通道暂时性开放,促进根系从培养液中吸收Ca2+。对蛋白质磷酸化的分析表明,4~8h的TCB胁迫促进水稻根系的蛋白质磷酸化,4~24h的TCB胁迫以及4~8h的Hg胁迫均促进水稻叶片的蛋白质磷酸化。从时间上来看,Hg和TCB胁迫对水稻蛋白质磷酸化的促进作用和Hg、TCB引起的水稻叶片或根系的第一个吸Ca2+高峰相一致。这表明,Hg和TCB胁迫对水稻蛋白质磷酸化的促进作用可能是由Hg和TCB胁迫促使水稻体内原生质Ca2+浓度提高所触发。而当TCB胁迫时间达到12h以后,TCB对水稻根系蛋白质磷酸化的抑制作用可能主要由于TCB对蛋白质激酶的抑制。Hg胁迫对水稻根系以及12h以后的TCB胁迫对水稻叶片蛋白质磷酸化的抑制作用,可能不仅因为Hg对蛋白激酶活性的抑制,而且还因为Hg对磷酸化蛋白表达的抑制。更多还原

【Abstract】 The effects of 1,2,4-Trichlorobenzene (TCB) and Mercury (Hg) stress on Ca2+ fluxion and protein phosphorylation in rice seedlings were investigated by radioisotope exchange kinetic method and in vitro phosphorylation assay. The results showed that, when rice roots exposed to 0.1 mmol.L-1 Hg and 5 mg.L-1 TCB within 48 h, the Ca2+ absorption in rice leaves was increased, and Ca2+ transportation from the roots to leaves was enhanced significantly. Hg and TCB exposure for 8 h caused Ca2+ channels located on plasmmalemma to open transiently. TCB exposure for 4~8 h or 4~24 h enhanced the protein phosphorylation in the roots or leaves respectively, and Hg exposure for 4~8 h also enhanced the protein phosphorylation in the leaves. The increases of protein phosphorylation corresponded with the first Ca2+ absorption peak, which confirmed that the enhancement of protein phosphorylation caused by TCB or Hg stress might be partly triggered by the increase of cytosolic Ca2+. The results also showed that long time (up to 12 h) TCB stress inhibiting protein phosphorylation in rice roots might be partly due to the inhibition of TCB on protein kinase activity. Hg stress inhibiting protein phosphorylation in rice roots and long time (up to 12 h) Hg stress inhibiting protein phosphorylation in rice leaves might be due to that, not only the protein kinase activity, but also the expression of phosphorylation proteins might be inhibited by Hg stress.更多还原