School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok 10150, Thailand.
Sci Total Environ. 2019 Apr 20;662:805-815. doi: 10.1016/j.scitotenv.2019.01.258. Epub 2019 Jan 23.
Benzene, a hydrophobic xenobiotic, induces cell damage in both humans and plants. Due to its volatilization, benzene is an airborne environmental problem. The potential of an exogenous bioactive brassinosteroid phytohormone to enhance benzene removal for phytoremediation was investigated. Chlorophytum comosum had higher brassinosteroids content under benzene stress. Plant treated with 24-epibrassinolide (EBR) removed significantly more gaseous benzene than untreated plants under both light and dark conditions at an initial benzene of 12.75 μmol in the systematic chambers (P < 0.05). Although benzene increased malondialdehyde in plant tissue, EBR-treated plants lowered this lipid peroxidation by enhancing their antioxidant content and increasing benzene detoxification-related genes expression, including ascorbic acid (AsA), homogentisate phytyltransferase (HPT), and glutathione synthethase (GS). This contributed to maintaining higher photosynthetic performances. Moreover, EBR-treated plants had higher gene expression of ferredoxin-NADP reductase (FNR) and glucose-6-phosphate 1-dehydrogenase (G6PDH), thus promoting NADPH biosynthesis to cope with benzene under light and dark conditions, respectively. Further, higher glutathione biosynthesis promoted more glutathione conjugate of benzene products including S-phenylcysteine (SPC) in EBR-treated plants. Hence, application of exogenous EBR as foliar spray provided for enhanced benzene detoxification via antioxidant content, benzene detoxification-related genes and benzene conjugation products with glutathione (GSH) and consequently greater gaseous benzene removal.
苯是一种疏水性的外来化合物，会对人类和植物造成细胞损伤。由于其挥发性，苯是一种空气传播的环境问题。本研究探讨了一种外源性生物活性油菜素甾体植物激素增强苯去除能力，从而促进植物修复的可能性。在苯胁迫下，吊兰中的油菜素内酯含量更高。在系统室中，初始苯浓度为 12.75μmol 时，与未处理的植物相比，用 24-表油菜素内酯（EBR）处理的植物在光照和黑暗条件下都能显著去除更多的气态苯（P<0.05）。虽然苯增加了植物组织中的丙二醛含量，但 EBR 处理的植物通过增强抗氧化剂含量和增加与苯解毒相关的基因表达，如抗坏血酸（AsA）、胡桐异戊烯基转移酶（HPT）和谷胱甘肽合酶（GS），降低了这种脂质过氧化作用。这有助于维持更高的光合作用性能。此外，EBR 处理的植物的铁氧还蛋白-NADP 还原酶（FNR）和葡萄糖-6-磷酸 1-脱氢酶（G6PDH）基因表达更高，从而分别在光照和黑暗条件下促进 NADPH 的生物合成以应对苯。此外，更高的谷胱甘肽生物合成促进了更多的谷胱甘肽结合的苯产物，包括 EBR 处理的植物中的 S-苯丙氨酸（SPC）。因此，外源性 EBR 的叶面喷施应用通过抗氧化剂含量、与苯解毒相关的基因和与谷胱甘肽（GSH）的苯共轭产物提供了增强的苯解毒作用，从而更有效地去除气态苯。
