β-Glucosidases as dominant dose-dependent regulators of Oryza sativa L. in response to typical organic pollutant exposures
β-Glucosidases as dominant dose-dependent regulators of Oryza sativa L. in response to typical organic pollutant exposures
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β-葡萄糖苷酶作为水稻对典型有机污染物暴露的主要剂量依赖性调节剂
DOI：
10.1016/j.envpol.2022.119709
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Zhu Lizhong
中科院分区：
文献类型：
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作者：
Shao Zexi;Liu Na;Wang Wei;Zhu Lizhong
了解维持体内平衡的代谢防御和补偿对评估有机污染物对作物的潜在健康风险至关重要。目前，对污染物胁迫下的靶向代谢途径和反应机制了解有限。本研究表明，环丙沙星（CIP）在环境浓度（1、5、25、50 mg/L）下对水稻生长没有明显的抑制作用，也没有造成严重的氧化损伤。相反，CIP浓度的增加引起了一系列以初级和次级代谢紊乱为主要特征的序列代谢紊乱，包括苯丙类生物合成、碳水化合物、脂质和氨基酸代谢。当CIPin在体内超过一定阈值水平（0.29 mg/g干重）后，β-葡萄糖苷酶（BGLUs）介导了水稻从苯丙素生物合成相关基因的激活到碳水化合物代谢相关基因的抑制的转变。其中，淀粉和蔗糖代谢受环境浓度（5 mg/L）和其他有机污染物（10 μg/L的三环唑、噻虫嗪、多溴联苯醚和多氯联苯）的影响最大。此外，编码内切葡聚糖酶和BGLU的关键基因（|log2FC| > 3.0）在100 μg/L其他被测试有机污染物下显著下调，支持从激活次生防御代谢到破坏初级能量代谢的转变。因此，除了生物积累外，BGLU活性和淀粉、蔗糖代谢的变化可以反映污染物对水稻的潜在不利影响。本研究解释了水稻对有机污染物的逐步代谢和转录响应，为综合评价有机污染物的环境风险提供了新的参考。
Understanding the metabolic defense and compensation to maintain homeostasis is crucial for assessing the potential health risk of organic pollutants in crops. Currently, limited understanding is available regarding the targeted metabolic pathways and response mechanism under contaminant stress. This study showed that ciprofloxacin (CIP) at the environmental concentrations (1, 5, 25, 50 mg/L) did not significantly inhibit growth or cause severe oxidative damage to rice (Oryza sativaL.). Instead, the increment in CIP concentration induced a series of sequential metabolic disorders, which were characterized predominantly by primary and secondary metabolic disturbances, including phenylpropanoid biosynthesis, the carbohydrate, lipid and amino acid metabolism. After CIPin vivoexceeded a certain threshold level (>0.29 mg/g dry weight), β-glucosidases (BGLUs) mediated the transition from the activation of the genes related to phenylpropanoid biosynthesis to the inhibition of the genes related to carbohydrate metabolism in rice. In particular, starch and sucrose metabolism showed the most profound perturbation stressed by environmental concentrations of CIP (5 mg/L) and other tested organic pollutants (10 μg/L of tricyclazole, thiamethoxam, polybrominated diphenyl ethers, and polychlorinated biphenyls). Besides, the key genes encoding endoglucanase and BGLU were significantly downregulated (|log2FC| > 3.0) under 100 μg/L of other tested organic pollutants, supporting the transition from the activation of secondary defense metabolism to the disruption of primary energy metabolism. Thus, in addition to bioaccumulation, changes in BGLU activity and starch and sucrose metabolism can reflect the potential adverse effects of pollutants on rice. This study explained the stepwise metabolic and transcriptional responses of rice to organic pollutants, which provided a new reference for the comprehensive evaluation of their environmental risks.