Evaluation of amino acid profile in contrasting arsenic accumulating rice genotypes under arsenic stress
Evaluation of amino acid profile in contrasting arsenic accumulating rice genotypes under arsenic stress
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DOI：
10.1007/s10535-014-0435-4
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发表时间：
2014-12-01
影响因子：
1.5
通讯作者：
Tripathi, R. D.
中科院分区：
文献类型：
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作者：
Kumar, A.;Dwivedi, S.;Tripathi, R. D.
重金属胁迫下，氨基酸在植物体内金属结合、抗氧化防御和信号转导等方面发挥重要作用。本研究以砷积累水稻基因型为材料，研究了砷积累水稻基因型在水培条件下添加砷酸盐（As-V）和亚砷酸盐（As-III）对水稻必需氨基酸（EAAs）、非必需氨基酸（NEAAs）以及脯氨酸和半胱氨酸生物合成途径相关酶的影响。在轻度砷胁迫下，两种水稻基因型的总砷含量均显著增加，低砷积累水稻基因型（LAARG; IET-19226）的增加幅度大于高砷积累水稻基因型（HAARG; BRG-12）。在等摩尔浓度（10 μ M），作为-III有一个更大的影响EAA比作为-V。相反，作为-V是更有效地诱导脯氨酸积累比作为-III。在NEAA中，As显著诱导组氨酸、天冬氨酸和丝氨酸的积累。相比之下，较高的As浓度（50 μ M）减少了大多数AAs的含量，在As-III曝光的效果更加突出。HAARG中谷氨酸激酶活性受到抑制，丝氨酸乙酰转移酶和半胱氨酸合成酶活性增加，与半胱氨酸合成呈正相关。
Amino acids (AAs) play significant roles in metal binding, antioxidant defense, and signaling in plants during heavy metal stress. In the present study, the essential amino acids (EAAs), non-essential amino acids (NEAAs), as well as the enzymes of proline and cysteine biosynthetic pathways were studied in contrasting arsenic accumulating rice genotypes grown in hydroponic solutions with addition of arsenate (As-V) or arsenite (As-III). Under a mild As stress, the total AAs content significantly increased in both the rice genotypes with a greater increase in a low As accumulating rice genotype (LAARG; IET-19226) than in a high As accumulating rice genotype (HAARG; BRG-12). At the equimolar concentration (10 mu M), As-III had a greater effect on EAAs than As-V. Conversely, As-V was more effective in inducing a proline accumulation than As-III. Among NEAAs, As significantly induced the accumulation of histidine, aspartic acid, and serine. In contrast, a higher As concentration (50 mu M) reduced the content of most AAs, the effect being more prominent during As-III exposure. The inhibition of glutamate kinase activity was noticed in HAARG, conversely, serine acetyltransferase and cysteine synthase activities were increased which was positively correlated with the cysteine synthesis.