高等植物对磷饥饿胁迫的自我拯救

Self rescue of Higher Plants to Phosphorus Starvations

低磷营养胁迫下，高等植物会采取一系列自我拯救措施，包括将生长环境中的难溶性无机磷和无效态有机磷活化或水解释放有效磷（Ｐｉ）、对低浓度有效磷的有效吸收以及对吸收的有限磷源的有效利用．适于这些自我拯救措施，体内的许多生理生化过程将经受重大调整，这涉及到许多蛋白和酶的含量及活性的变化．与自我拯救密切相关的酶和蛋白的合成大量增加，有些则不同程度地减弱．有些酶，即使酶蛋白含量大大减少，但特殊的活性调节机制使其活性几乎未减弱甚至略有提高．本文主要概述磷饥饿状态下，呼吸和光合作用过程中的几种酶、与有机磷利用有关的酶的变化，例如酸性磷酸酶、ＲＮＡ酶、有关的蛋白激酶以及高亲和力Ｐｉ转运蛋白等．

During phosphorus starvation,higher plants actively take many measures to make self rescue,including the transformation of unavailable inorganic phosphorus into available form (Pi),release of Pi through the hydrolysis of unavailable organic phosphorus by acid phosphatases,or RNases;enhancement of absorption to extremely low concentration available phosphorus;and the efficient utilization to absorbed limited phosphorus source. Adapting to the self rescue, many physiological and biochemical processes would be greatly modified.These refer to the great increase of some protein content and the activity of some enzymes closely related to the rescue.And also,some other proteins and enzymes would face to the decrease with the varied extents both on the content and the activity.Interestingly,for some enzymes,although the amount of enzyme proteins are greatly decreasing,the activity is almost no change,and even slightly enhanced.In this paper,the related advances in this research field were summarized.