Chu Yu-Tan, Li Yan, Huang Yi-Zong, Bao Qiong-Li, Sun Hong-Yu, Huang Yong-Chun
Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
Huan Jing Ke Xue. 2023 Apr 8;44(4):2356-2364. doi: 10.13227/j.hjkx.202205297.
To investigate the effect of exogenous application of melatonin (MT) on rice seedlings under antimony (Sb) stress, hydroponic experiments were carried out with rice seedlings (Huarun No.2). The fluorescent probe localization technology was used to locate the reactive oxygen species (ROS) in the root tips of rice seedlings, and the root viability, malondialdehyde (MDA) content, ROS (HO and O·) content, antioxidant enzyme (SOD, POD, CAT, and APX) activities, and antioxidant (GSH, GSSG, AsA, and DHA) contents in the roots of rice seedlings were analyzed. The results showed that exogenous addition of MT could alleviate the adverse effects of Sb stress on the growth and increase the biomass of rice seedlings. Compared with the Sb treatment, the application of 100 μmol·L MT increased rice root viability and total root length by 44.1% and 34.7% and reduced the content of MDA, HO and O· by 30.0%, 32.7%, and 40.5%, respectively. Further, the MT treatment increased the activities of POD and CAT by 54.1% and 21.8%, respectively, and also regulated the AsA-GSH cycle. This research indicated that exogenous application of 100 μmol·LMT can promote the growth and antioxidant ability of rice seedlings and alleviate the damage of lipid peroxidation by Sb stress, thus improving the resistance of rice seedlings under Sb stress.
为了研究外源施加褪黑素（MT）对锑（Sb）胁迫下水稻幼苗的影响，以水稻品种华润2号幼苗进行水培试验。采用荧光探针定位技术对水稻幼苗根尖中的活性氧（ROS）进行定位，并分析水稻幼苗根系活力、丙二醛（MDA）含量、ROS（HO和O·）含量、抗氧化酶（超氧化物歧化酶、过氧化物酶、过氧化氢酶和抗坏血酸过氧化物酶）活性以及根系中抗氧化剂（谷胱甘肽、氧化型谷胱甘肽、抗坏血酸和脱氢抗坏血酸）含量。结果表明，外源添加MT可以缓解Sb胁迫对水稻幼苗生长的不利影响并增加其生物量。与Sb处理相比，施加100 μmol·L MT使水稻根系活力和总根长分别提高了44.1%和34.7%，MDA、HO和O·含量分别降低了30.0%、32.7%和40.5%。此外，MT处理使过氧化物酶和过氧化氢酶活性分别提高了54.1%和21.8%，还调节了抗坏血酸-谷胱甘肽循环。该研究表明，外源施加100 μmol·L MT可以促进水稻幼苗的生长和抗氧化能力，减轻Sb胁迫对脂质过氧化的损伤，从而提高水稻幼苗在Sb胁迫下的抗性。
