Citrulline, a novel compatible solute in drought‐tolerant wild watermelon leaves, is an efficient hydroxyl radical scavenger

FEBS Letters

Yokota, Akiho¹  Akashi, Kinya¹  Miyake, Chikahiro¹ 

[1] Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0101, Japan

关键词: Citrulline;    Hydroxyl radical scavenger;    Drought tolerance;    Wild watermelon (Citrullus lanatus L.);    ROS;    reactive oxygen species;    DHBA;    2;    3-dihydroxy-benzoic acid;    ID50;    the concentration of a compound required to inhibit hydroxyl radical-catalyzed hydroxylation of salicylate by 50% of the maximum yield observed in the absence of the compound;    MDH;    malate dehydrogenase;    LDH;    lactate dehydrogenase;    PK;    pyruvate kinase;    LC/MS;    liquid chromatography-mass spectrometry;   

DOI  :  10.1016/S0014-5793(01)03123-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Drought-tolerant wild watermelon accumulates high levels of citrulline in the leaves in response to drought conditions. In this work, the hydroxyl radical-scavenging activity of citrulline was investigated in vitro. The second-order rate constant for the reaction between citrulline and hydroxyl radicals was found to be 3.9×10⁹ M⁻¹ s⁻¹, demonstrating that citrulline is one of the most efficient scavengers among compatible solutes examined so far. Moreover, citrulline effectively protected DNA and an enzyme from oxidative injuries. Liquid chromatography-mass spectrometry analysis revealed that at least four major products were formed by the reaction between citrulline and hydroxyl radicals. Activities of metabolic enzymes were not inhibited by up to 600 mM citrulline, indicating that citrulline does not interfere with cellular metabolism. We reasoned, from these results, that citrulline contributes to oxidative stress tolerance under drought conditions as a novel hydroxyl radical scavenger.

【 授权许可】

Unknown