Rubisco activities, properties, and regulation in three different C4 grasses under drought.
Rubisco activities, properties, and regulation in three different C4 grasses under drought.
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干旱条件下三种不同 C4 草的 Rubisco 活性、特性和调节。
DOI：
10.1093/jxb/erq071
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发表时间：
2010-05
影响因子：
6.9
通讯作者：
Parry, Martin A. J.
中科院分区：
文献类型：
--
作者：
Carmo-Silva, A. Elizabete;Keys, Alfred J.;Andralojc, P. John;Powers, Stephen J.;Arrabaca, M. Celeste;Parry, Martin A. J.
在C4植物中，水分亏缺可能会降低光合CO2同化的气孔导度的变化独立，这表明减少营业额核酮糖-1，5-二磷酸羧化酶/加氧酶（Rubisco）。以百喜草、狗牙根和结缕草为材料，研究了Rubisco的活性和生化特性。我们的目标是在这些物种的C4 Rubisco的特点，并确定与干旱造成的光合速率下降的因素。从三种C4禾本科植物中分离的Rubisco具有较小的特异性因子（SC/O）、较大的CO2和O2米氏常数（Kc）和最大羧化速率（Vc），这与C4 Rubisco在维管束鞘中的CO2富集环境有关。在叶片脱水过程中，Rubisco的数量和最大活性保持不变，但初始和总活性略有下降，可能是由于抑制作用增强。紧结合抑制剂在光照下存在，但在黑暗中更丰富，特别是在Z。在干旱胁迫条件下，其数量增加。从黑叶木中提取抑制剂。鉴定为2-羧基阿拉伯糖醇-1-磷酸（CA 1 P）。与CA 1 P的存在一致，Rubisco的总活性在12 h黑暗后在Z.日本。叶片中的核酮糖-1，5-二磷酸（RuBP）减少与干旱胁迫，数量接近Rubisco催化位点。RuBP下降的幅度表明，至少在C. dactylon和Z.在干旱胁迫下，粳稻叶片光合作用下降，这可能是干旱胁迫导致的光合作用下降的原因之一。
In C4 plants, water deficit may decrease photosynthetic CO2 assimilation independently of changes in stomatal conductance, suggesting decreased turnover by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The activity and biochemistry of Rubisco was studied in three different C4 grasses: Paspalum dilatatum, Cynodon dactylon, and Zoysia japonica. The objectives were to characterize the C4 Rubisco in these species and to identify factors associated with decreased photosynthetic rates caused by drought. Rubisco isolated from each of the three C4 grasses was characterized by smaller specificity factors (SC/O), larger Michaelis–Menten constants for CO2 (Kc) and O2 (Ko), and larger maximum carboxylation velocities (Vc) than Rubisco from wheat, which can be rationalized in terms of the CO2-rich environment of C4 Rubisco in the bundle sheath. During leaf dehydration the quantity and maximum activity of Rubisco remained unchanged but the initial and total activities declined slightly, possibly due to increased inhibition. Tight-binding inhibitors were present in the light but were more abundant in the dark, especially in Z. japonica, and increased in quantity with drought stress. The inhibitor from darkened leaves of Z. japonica was identified as 2-carboxyarabinitol-1-phosphate (CA1P). Consistent with the presence of CA1P, the total activity of Rubisco was decreased after 12 h darkness in Z. japonica. Ribulose-1,5-bisphosphate (RuBP) in the leaves decreased with drought stress, to quantities approximating those of Rubisco catalytic sites. The magnitude of the decrease in RuBP suggested that, at least in C. dactylon and Z. japonica, it could contribute to the drought-induced decrease in photosynthesis.
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影响因子：
2.9
作者：
BADGER, MR;LORIMER, GH
通讯作者：
LORIMER, GH
影响因子：
3
作者：
Carmo-Silva, Ana E.;Soares, Ana S.;Arrabaca, Maria Celeste
通讯作者：
Arrabaca, Maria Celeste
影响因子：
4.2
作者：
Flexas, J;Medrano, H
通讯作者：
Medrano, H
影响因子：
64.8
作者：
JORDAN, DB;OGREN, WL
通讯作者：
OGREN, WL
影响因子：
7.4
作者：
Kane, HJ;Wilkin, JM;Andrews, TJ
通讯作者：
Andrews, TJ