Enhanced photosynthesis and growth of transgenic plants that express ictB, a gene involved in HCO3- accumulation in cyanobacteria
Enhanced photosynthesis and growth of transgenic plants that express ictB, a gene involved in HCO3- accumulation in cyanobacteria
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DOI：
10.1046/j.1467-7652.2003.00003.x
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发表时间：
2003-01-01
影响因子：
13.8
通讯作者：
Kaplan, A
中科院分区：
文献类型：
--
作者：
Lieman-Hurwitz, J;Rachmilevitch, S;Kaplan, A
转基因拟南芥和烟草植物，表达ictB，一个基因参与HCO 3-积累的蓝藻聚球藻属PCC 7942内，表现出显着更快的光合速率比野生型下限制，但不饱和CO2浓度。在低相对湿度条件下，转基因A.拟南芥植物比野生型快得多。在潮湿条件下没有观察到这种生长的增强。在野生型和它们各自的转基因植物中检测到的核酮糖1，5-二磷酸羧化酶/加氧酶（RubisCO）的量没有差异。在体外激活后，RubisCO的活动，无论是低或高湿度生长的转基因植物中观察到的野生型相似。相比之下，在低湿度下生长的植物中的体内RubisCO活性，即没有预先活化，在表达ictB的植物中比在其野生型中高得多。表达ictB的转基因植物中的CO2补偿点低于野生型，表明RubisCO附近的CO2浓度较高。这可能解释了转基因植株中RubisCO的高活化水平以及增强的光合活性和生长。这些数据表明ictB在刺激作物产量方面具有潜在的用途。
Transgenic Arabidopsis thaliana and Nicotiana tabacum plants that express ictB, a gene involved in HCO3- accumulation within the cyanobacterium Synechococcus sp. PCC 7942, exhibited significantly faster photosynthetic rates than the wild-types under limiting but not under saturating CO2 concentrations. Under conditions of low relative humidity, growth of the transgenic A. thaliana plants was considerably faster than the wild-type. This enhancement of growth was not observed under humid conditions. There was no difference in the amount of ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) detected in the wild-types and their respective transgenic plants. Following activation in vitro, the activities of RubisCO from either low- or high-humidity-grown transgenic plants were similar to those observed in the wild-types. In contrast, the in vivo RubisCO activity, i.e. without prior activation, in plants grown under low humidity was considerably higher in ictB-expressing plants than in their wild-types. The CO2 compensation point in the transgenic plants that express ictB was lower than in the wild-types, suggesting that the concentration of CO2 in close proximity to RubisCO was higher. This may explain the higher activation level of RubisCO and enhanced photosynthetic activities and growth in the transgenic plants. These data indicated a potential use of ictB for the stimulation of crop yield.