Kang Yi, Li Cheng-Zhi, Ullah Abid, Zhang Qing, Yu Xiao-Zhang
College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541004, China.
Toxics. 2024 Aug 8;12(8):577. doi: 10.3390/toxics12080577.
Potential toxic element (PTE) pollution has emerged as a significant environmental and social concern in global agriculture. Chromium (Cr) occurs in different oxidation states naturally, among them Cr(VI), which is highly toxic. This study carried out biochemical and molecular tests to elucidate the accumulation of total soluble phenolics (TSPs) in rice plants exposed to Cr(VI) at 2.0, 8.0, and 16.0 mg Cr/L, emphasizing the interaction between polyamines (PAs) and abscisic acid (ABA). The results revealed significant Cr accumulation in different tissues of rice plants, which hindered their growth. Cr(VI) exposure increased the ABA concentration, with higher levels detected in the shoots than in the roots. The TSP concentration in rice tissues showed a positive relationship with the supplied concentrations of Cr(VI). The measured PAs, including spermine (Spm), putrescine (Put), and spermidine (Spd), exhibited varied responses to Cr(VI) stress, with only Spm concentration increasing with Cr(VI) concentrations. Real-time qRT-PCR showed PAs and ABA synthesis-associated genes such as , , , and were significantly up-regulated in shoot of rice plants treated with Cr(VI). These genes are associated with the second pathway of Put synthesis, originating from Arg. Almost all genes activated in the Met pathway were significantly up-regulated as well. Moreover, the genes involved in the interconversion among the three species of PAs exhibited completely different responses to Cr(VI) exposure. Overall, the biochemical analysis and gene expression data indicate that the interaction between ABA and Spm is likely to enhance the TSP levels in rice plants subjected to Cr(VI) toxicity.
潜在有毒元素（PTE）污染已成为全球农业领域一个重大的环境和社会问题。铬（Cr）以不同氧化态自然存在，其中Cr（VI）具有高毒性。本研究进行了生化和分子测试，以阐明水稻植株在暴露于浓度为2.0、8.0和16.0 mg Cr/L的Cr（VI）时总可溶性酚类（TSPs）的积累情况，重点研究了多胺（PAs）与脱落酸（ABA）之间的相互作用。结果表明，水稻植株不同组织中Cr积累显著，阻碍了其生长。暴露于Cr（VI）会增加ABA浓度，地上部检测到的ABA水平高于根部。水稻组织中TSP浓度与所供应的Cr（VI）浓度呈正相关。所测定的多胺，包括精胺（Spm）、腐胺（Put）和亚精胺（Spd），对Cr（VI）胁迫表现出不同的响应，只有Spm浓度随Cr（VI）浓度增加。实时定量逆转录聚合酶链反应（qRT-PCR）显示，在经Cr（VI）处理的水稻植株地上部，与PAs和ABA合成相关的基因如[此处原文缺失具体基因名称]显著上调。这些基因与Put合成的第二条途径相关，该途径起源于精氨酸（Arg）。几乎所有在蛋氨酸（Met）途径中被激活的基因也显著上调。此外，参与三种多胺相互转化的基因对Cr（VI）暴露表现出完全不同的响应。总体而言，生化分析和基因表达数据表明，ABA与Spm之间的相互作用可能会提高遭受Cr（VI）毒性的水稻植株中的TSP水平。
