Effects of Exogenous ABA on Physiological Characteristics and Gene Expression in Sugarcane Seedlings under Drought Stress
Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2023, Vol. 44 ›› Issue (3): 553-561.DOI: 10.3969/j.issn.1000-2561.2023.03.012

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

Effects of Exogenous ABA on Physiological Characteristics and Gene Expression in Sugarcane Seedlings under Drought Stress

NONG Qian1,2, XIE Jinlan1, LIN Li1, MO Zhanghong1, WANG Zeping1, SONG Xiupeng1, LI Changning1,*()   

  1. 1. Guangxi Key Laboratory of Sugarcane Genetic Improvement / Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture & Rural Affairs, Nanning, Guangxi 530007, China
    2. Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pest / Plant Protection Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi 530007, China
  • Received:2022-05-10 Revised:2022-06-27 Online:2023-03-25 Published:2023-04-23
  • Contact: *LI Changning,E-mail:lcn560@163.com

Abstract:

Sugarcane is an important sugar crop in the world, but the main sugarcane producing areas in China are hilly and dry slopes, and seasonal droughts occur frequently due to the uneven distribution of rainfall. Droughts do great harm to yield and quality and the sustainable development of sugarcane industry in China. The plant hormone abscisic acid (ABA) not only regulates plant growth and development, but also plays an important role in the physiological and biochemical responses of plants environmental stresses. In this study, we used sugarcane (Saccharum officinarum L.) variety ‘Guitang 42’ as the material to investigate the effects of exogenous ABA on leaf physiological characteristics and gene expressions under water stress condition in treatments control (normal irrigation), control+ABA, drought (stop irrigation), drought+ABA. The foliar application of 15 μmol/L ABA was sprayed twice in two days before drought stress given. The results showed that the changes of main physiological and biochemical parameters and gene expression in control+ABA treatment were not significantly different from those of the control. The leaf relative water content (RWC) was gradually decreased by drought treatment but it could maintain higher in drought+ABA treatment. The drought treatment could result in an increase in malondialdehyde (MDA) and hydrogen peroxide (H2O2) content, but the plants applied with ABA were found to resist the excessive accumulation of MDA. Drought stress significantly reduced the leaf chlorophyll content in sugarcane, but the exogenous ABA application decreased the degradation of chlorophyll, counteracted, at least in part, the decrease in quantum efficiency of PSII (ΦPSII). The expression of gene encoding 9-cis-epoxycarotenoid dioxygenase (NCED) for ABA biosynthesis, the genes encoding Δ1-pyrroline-5-carboxylate synthase (P5CS) for proline biosynthesis, and the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD) encoding genes was significantly increased in the leaf under water stress condition, following the significantly higher endogenous ABA content, proline content and CAT, SOD, APX and POD activities in water stress treatment as compared to the control. But exogenous ABA application under water stress could further enhance the expression of the genes, hence further improved the ABA content, proline content and related antioxidant enzyme activity. The results clearly suggests that the foliar ABA application could triggering the over expression of antioxidative defense system, and improve drought tolerance of sugarcane under water stress condition.

Key words: sugarcane, abscisic acid, drought stress, physiological characteristic, gene expression

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