Zhang Jing-Jing, Jiao Qiu-Juan, Xu Zheng-Yang, Fan Li-Na, Jiang Ying, Song Jia, Hua Dang-Ling, Li Ge-Zi, Lin Di, Liu Hai-Tao
College of Resources and Environment, Henan Agricultural University, Zhengzhou 450046, China.
National Engineering Research Center for Wheat, Henan Agricultural University, Zhengzhou 450046, China.
Huan Jing Ke Xue. 2024 Jun 8;45(6):3649-3660. doi: 10.13227/j.hjkx.202307207.
This research aimed to clarify the effects of exogenously applied chitosan on the physiological characteristics, antioxidant activities, and Cd accumulation of wheat ( L.) seedlings under cadmium (Cd) stress and to identify the key indicators based on the partial least squares model. The wheat variety studied was Bainong207 (BN207), and Cd-stress was achieved by growing seedlings in a hydroponic culture experiment with 10 and 25 μmol·L Cd added to the culture solution. It was found that both Cd-stress at 10 and 25 μmol·L significantly inhibited the chlorophyll content, photosynthesis, and biomass accumulation of wheat seedlings. Seedling roots became shorter and thicker, and the lateral roots decreased under Cd-stress. The Cd-stress also increased HO and MDA accumulation and the degree of cell membrane lipid peroxidation and affected the activities of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD). Under Cd stress, exogenous chitosan decreased the Cd content in the aboveground and underground parts of wheat by 13.22 %-21.63 % and 7.92 %-28.32 % and reduced Cd accumulation in the aboveground and underground parts by 5.37 %-6.71 % and 1.91 %-4.09 %, respectively. Whereas exogenous chitosan application significantly reduced the content of HO in roots and aboveground parts of wheat by 38.21 %-47.46 % and 45.81 %-55.73 % and MDA content by 37.65 %-48.12 % and 29.87 %-32.51 %, it increased the activities of SOD and POD in roots by 2.78 %-5.61 % and 13.81 %-18.33 %, respectively. In summary, exogenous chitosan can improve the photosynthetic characteristics and antioxidant enzyme activities of wheat seedlings under Cd stress, reduce the content and accumulation of Cd in the root and aboveground parts of wheat, and alleviate the damage of lipid peroxidation to the cell membrane. All of these results provide the basal data for the application of exogenous chitosan to alleviate Cd toxicity to wheat seedlings.
本研究旨在阐明外源壳聚糖对镉（Cd）胁迫下小麦（L.）幼苗生理特性、抗氧化活性及Cd积累的影响，并基于偏最小二乘模型确定关键指标。所研究的小麦品种为百农207（BN207），通过在水培试验中向培养液添加10和25 μmol·L的Cd来实现Cd胁迫。结果发现，10和25 μmol·L的Cd胁迫均显著抑制了小麦幼苗的叶绿素含量、光合作用及生物量积累。Cd胁迫下，幼苗根系变短变粗，侧根减少。Cd胁迫还增加了HO和MDA的积累以及细胞膜脂质过氧化程度，并影响了超氧化物歧化酶（SOD）和过氧化物酶（POD）等抗氧化酶的活性。在Cd胁迫下，外源壳聚糖使小麦地上部和地下部的Cd含量分别降低了13.22 %-21.63 %和7.92 %-28.32 %，地上部和地下部的Cd积累量分别降低了5.37 %-6.71 %和1.91 %-4.09 %。外源壳聚糖处理显著降低了小麦根系和地上部HO含量38.21 %-47.46 %和45.81 %-55.73 %，MDA含量37.65 %-48.12 %和29.87 %-32.51 %，同时使根系中SOD和POD活性分别提高了2.78 %-5.61 %和13.81 %-18.33 %。综上所述，外源壳聚糖可改善Cd胁迫下小麦幼苗的光合特性和抗氧化酶活性，降低小麦根和地上部Cd的含量及积累，减轻脂质过氧化对细胞膜的损伤。所有这些结果为外源壳聚糖缓解小麦幼苗Cd毒性的应用提供了基础数据。
