Feng Han-Qing, Ma Jun, Li Hong-Yu, Wan Dong-Shi, Li Xin, Liu Yan-Li, Liang Hou-Guo
School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
Zhi Wu Sheng Li Yu Fen Zi Sheng Wu Xue Xue Bao. 2006 Jun;32(3):300-6.
Under constant light, increases in V(t) (total respiration rate), V(alt) (capacity of alternative pathway), and V(alt)/V(t) ration values (Figs.1-3) in fully etiolated rice seedlings leaves were founded. Northern hybridization with special probes for rice AOX1a, AOX1b and AOX1c revealed that the AOX1c mRNA was mainly present under constant light (Fig.4). SHAM (salicylhydroxamic acid) decreased the relative oxygen evolution rate and chlorophyll content during the rapid greening of the etiolated rice seedlings (Figs.6, 7). We found that illumination caused bigger increase in V(alt) in fully etiolated rice seedlings than in any partially etiolated rice seedlings (Fig.8A), while the soluble sugar contents did not show any significant differences (Fig.8B). This revealed the connection between greening process and cyanide-resistant respiration in rice seedlings. We infer that one of the possible functions of the cyanide-resistant respiration is to maintain a high rate of respiratory electron transport for the essential biosynthesis processes at the early stage of chloroplast development. Cyanide-resistant respiration may provide a regulatory mechanism for the balance between the requirements of the energy and substances.
在持续光照下，发现完全黄化的水稻幼苗叶片中的V(t)（总呼吸速率）、V(alt)（交替途径容量）和V(alt)/V(t)比值增加（图1 - 3）。用针对水稻AOX1a、AOX1b和AOX1c的特异性探针进行Northern杂交显示，AOX1c mRNA主要在持续光照下存在（图4）。水杨基羟肟酸（SHAM）降低了黄化水稻幼苗快速绿化过程中的相对氧释放速率和叶绿素含量（图6、7）。我们发现，光照导致完全黄化的水稻幼苗中V(alt)的增加幅度大于任何部分黄化的水稻幼苗（图8A），而可溶性糖含量没有显示出任何显著差异（图8B）。这揭示了水稻幼苗绿化过程与抗氰呼吸之间的联系。我们推断，抗氰呼吸的可能功能之一是在叶绿体发育早期为基本生物合成过程维持高呼吸电子传递速率。抗氰呼吸可能为能量和物质需求之间的平衡提供一种调节机制。
