Possible involvement of some secondary metabolites in salt tolerance of sugarcane
Possible involvement of some secondary metabolites in salt tolerance of sugarcane
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DOI：
10.1016/j.jplph.2005.07.007
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发表时间：
2006-05-01
影响因子：
4.3
通讯作者：
Ghazanfar, Alia
中科院分区：
文献类型：
--
作者：
Wahid, Abdul;Ghazanfar, Alia
有毒离子在植物组织中的积累调节了初级和次级代谢产物的水平，这可能与耐盐性有关。在本研究中，两个甘蔗无性系CP-4333（耐受性）和HSF-240（敏感性）在形成阶段暴露于盐度水平，并以10天为间隔进行了三次评估。尽管两个无性系的净光合速率、叶面积、茎长和干重均有所下降，但CP-4333的下降幅度小于HSF-240。两个无性系均表现出Na+、Cl-积累和少量K+积累的趋势，但CP-4333的Na+积累较少，K+积累较多，因此K+:Na+比值较高。类胡萝卜素（CAR）含量保持稳定，而总叶绿素（CHL）含量在抗性无性系中略有降低，在HSF-240中显著降低。CP-4333的可溶性酚类物质（PHE）、花青素（ANT）和黄酮（FLA）含量分别是HSF-240的2.5倍、2.8倍和3.0倍。敏感性无性系表现出Pn和大多数次生代谢物的减少，而耐受性无性系则没有，这表明这些代谢物的存在与甘蔗耐盐性的提高有关。PHE、ANT和FLA合成的增加似乎可以保护甘蔗免受离子诱导的氧化应激，这可能是由于这些代谢物具有共同的结构骨架——苯基。CAR作为光收获中心（LHC）的组成部分，在叶绿体中生物合成，可能赋予对该细胞器的抗性。在细胞质中合成的PHE、ANT和FLA可能通过结合离子来保护细胞免受离子诱导的氧化损伤，从而降低对细胞质结构的毒性。(c) 2005 Elsevier GmbH版权所有。
Accumulation of toxic ions in plant tissues modulates the levels of primary and secondary metabolites, which may be related to salinity tolerance. In this study two sugarcane clones, CP-4333 (tolerant) and HSF-240 (sensitive), were exposed to salinity levels at the formative stage, and evaluated three times at 10-day intervals. Although net rate of photosynthesis (Pn), leaf area, length and dry weight of shoots were decreased in both clones, the CP-4333 showed less reduction compared to HSF-240. Both clones displayed a general tendency to accumulate Na+ and Cl- and little K+, though CP-4333 accumulated less Na+ and more K+ compared to HSF-240, and thus showed a higher K+:Na+ ratio. The carotenoid (CAR) content remained steady, while total chlorophyll (CHL) was slightly reduced in the tolerant clone and significantly reduced in HSF-240. In contrast, soluble phenolics (PHE), anthocyanins (ANT) and flavones (FLA) levels were 2.5, 2.8 and 3.0 times greater in CP-4333 in comparison with HSF-240. The decrease in Pn and most secondary metabolites demonstrated by the sensitive clone, but not evidenced in the tolerant clones, suggest that the presence of those metabolites is related to increased salt tolerance of sugarcane. The increased synthesis of PHE, ANT and FLA seems to protect sugarcane from ion-induced oxidative stress, probably due to a common structural skeleton, the phenyl group, of those metabolites. CAR, as components of the light harvesting center (LHC) and biosynthesized in chloroplasts, may confer resistance to this organelle. The PHE, ANT and FLA synthesized in the cytosol may protect cells from ion-induced oxidative damage by binding the ions and thereby showing reduced toxicity on cytoplasmic structures. (c) 2005 Elsevier GmbH. All rights reserved.