The effect of lead on photosynthesis and respiration in detached leaves and in mesophyll protoplasts of Pisum sativum
The effect of lead on photosynthesis and respiration in detached leaves and in mesophyll protoplasts of Pisum sativum
复制标题
DOI：
10.1007/s11738-998-0064-7
复制
发表时间：
1998-01-01
影响因子：
2.6
通讯作者：
Poskuta, JW
中科院分区：
文献类型：
--
作者：
Parys, E;Romanowska, E;Poskuta, JW
豌豆离体叶片的光合和蒸腾速率。CV. Ilowiecki）暴露于1或5个mmol.dm的Pb（NO_3）（2）溶液中时，抑制。较高浓度的这种有毒物质降低光合作用和蒸腾速率分别为2和3倍，呼吸增加约20%，作为测量后24小时的治疗。与Pb（NO_3）（2）相似，甘油醛溶液（一种磷酸核酮糖激酶抑制剂）在50mmol.dm-3）浓度下，在引入豌豆叶片期间降低光合速率和蒸腾速率。在Pb（NO3）（2）浓度为5（-3）时，PS Ⅱ的潜在光化学效率（Fv/Fm）和Rubisco活性（EC mmol.dm）4.1.1.39无论是在PEPC（EC 4.1.1.31）的活性或蛋白质和色素含量的变化，在铅处理的叶片。mmol.dm浓度为5的Pb（NO_3）（2）处理24和48小时，叶片原生质体的光合活性分别下降10%和25%，而暗呼吸速率分别提高约40%和75%。mmol.dmPb（NO3）（2）溶液处理豌豆离体叶片24 h，脱落酸（一种负责气孔关闭的激素）的含量增加了约3倍;更长时间（48 h）处理导致该激素的量进一步增加（约7倍）。我们的实验结果提供的证据表明，CO2固定在离体豌豆叶片，至少长达24小时的Pb（NO3）（2）处理，主要是由气孔关闭限制。
Photosynthesis and transpiration rate of detached leaves of pea (Pisum sativum L. cv. Ilowiecki) exposed to solution of Pb(NO3)(2) at 1 or 5 mmol.dm(-3) concentrations were inhibited. The higher concentration of this toxicant decreased photosynthesis and transpiration rates 2 and 3 times respectively, and increased respiration by about 20 %, as measured after 24 hours of treatment. Similarly to Pb(NO3)(2), glyceraldehyde solution, an inhibitor of phosphoribulokinase, at 50 mmol.dm(-3) concentration decreased the rates of photosynthesis and transpiration during introduction into pea leaves. The rate of dark respiration, however, remained unchanged during 2 hours of experiment.The potential photochemical efficiency of PS II (Fv/Fm) and the activity of Rubisco (EC 4.1.1.39) at 5 mmol.dm(-3) of Pb(NO3)(2) were lowered by 10 % and 20 % respectively, after 24 hours. Neither changes in the activity of PEPC (EC 4.1.1.31) or protein and pigment contents were noted in Pb-treated leaves. The photosynthetic activity of protoplasts isolated from leaves treated for 24 or 48 hours with Pb(NO3)(2) at 5 mmol.dm(-3) concentration was decreased 10 % or 25 %, whereas, the rate of dark respiration was stimulated by-about 40 % and 75 %, respectively. The content of abscisic acid, a hormone responsible for stomatal closure, in detached pea leaves treated for 24 h with 5 mmol.dm(-3) of Pb(NO3)(2) solution was increased by about 3 times; a longer (48 h) treatment led to further increase (by about 7 times) in the amount of this hormone. The results of our experiments provide evidences that CO2 fixation in detached pea leaves, at least up to 24 hours of Pb(NO3)(2) treatment, was restricted mainly by stomatal closure.