Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2021, Vol. 42 ›› Issue (9): 2616-2622.DOI: 10.3969/j.issn.1000-2561.2021.09.024

• Plant Cultivation, Physiology & Biochemistry • Previous Articles     Next Articles

Impacts of Exogenous Nitric Oxide on Growth of Alfalfa Seedlings Exposed to Aluminum Stress

ZHANG Yan1, PENG Kaiyue1,2, MA Xiangli1, WANG Hui1, LING Rugui1, REN Jian1,**()   

  1. 1. College of Animal Science and Technology, Yunnan Agricultural University, Kunming, Yunnan 650201, China
    2. Gucheng Animal Husbandry and Veterinary Center Station, Wuxiang, Shanxi 046302, China
  • Received:2020-11-02 Revised:2020-12-04 Online:2021-09-25 Published:2021-11-01
  • Contact: REN Jian


The effects of exogenous nitric oxide (NO) application on the morphological and physiological characteristics of alfalfa (WL525HQ) seedlings under aluminum stress (0.1 mmol/L) were studied through hydroponics to reveal the physiological mechanism of NO alleviating aluminum toxicity of alfalfa. The results indicated that aluminum stress inhibited the growth of alfalfa seedlings shown by the significant decrease in plant height, root length, leaf area, aboveground and belowground biomass. Free proline content and superoxide dismutase (SOD) activity in the leaves were significantly reduced, whereas proline in the roots was significantly increased (P<0.05). Exogenous NO application affected its morphological and physiological responses to aluminum stress, and it was related to the concentration applied. Low concentration of exogenous NO alleviated the inhibiting effect of aluminum stress on the main root length. Medium concentration increased plant height, surface area and volume of root system under aluminum stress, which led to increases of above and below ground biomass. High concentration significantly increased free proline and SOD activity. In summary, exogenous NO alleviates the inhibitory effect of aluminum stress on the growth of alfalfa seedlings through processes like free proline accumulation and SOD, hence, contribute to enhancement of above and below ground biomass.

Key words: Medicago sativa, free proline, sodium nitroprusside (SNP), superoxide dismutase (SOD)

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