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ORIGINAL RESEARCH article

Front. Plant Sci.
Sec. Plant Abiotic Stress
Volume 15 - 2024 | doi: 10.3389/fpls.2024.1498123

Cytokinin modulates the inhibitory effect of shade stress on photosynthesis, antioxidant capacity and hormone homeostasis to regulate the grain yield in wheat

Provisionally accepted
Yongqiang Zhang Yongqiang Zhang 1,2,3*Juan Li Juan Li 2,3*Qijiang Xu Qijiang Xu 2,3*Chuanxin Chen Chuanxin Chen 2,3*Shihui Nie Shihui Nie 2,3*Junjie Lei Junjie Lei 2,3*Liusheng Duan Liusheng Duan 1*
  • 1 College of Agronomy and Biotechnology, China Agricultural University, Beijing, Beijing Municipality, China
  • 2 Xinjiang Academy of Agricultural Sciences, Urumqi, China
  • 3 Key Laboratory of Desert-Oasis Crop Physiology, Ecology and Cultivation, Urumqi, China

The final, formatted version of the article will be published soon.

    Agroforestry intercropping is an effective way to optimize land use and ensure food security. However, the physiological mechanism by which the shading of dominant plants inhibits the yield of non-dominant plants in this mode remains to be investigated. A two-year location experiment of walnut-winter wheat intercrop combined with exogenous 6-benzyladenine (6-BA, the first synthetic cytokinin) treatment was conducted to reveal the mechanism of 6-BA in inhibiting wheat growth and yield formation under shade stress by measuring the photosynthetic characteristics, antioxidant capacity, hormone homeostasis of wheat flag leaves and yield. The results showed that compared with far canopy area (FCA), antioxidant enzyme activity [e.g. superoxide dismutase (SOD), peroxidase (POD)], zeatin (ZT) and abscisic acid (ABA) content and photosynthesis of wheat flag leaves were significantly reduced in below canopy area (BCA) treatment during flowering and grain filling stages, thereby inhibiting wheat dry matter accumulation and yield formation. Exogenous 6-BA significantly increased hormone [i.e. indoleacetic acid (IAA), ZT and gibberellin (GA)] levels, antioxidant enzyme activities and photosynthesis in flag leaves, thereby increasing dry matter and yield, especially in the FCA condition. Furthermore, net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), activities of ribulose bisphosphate carboxylase (RuBPCase) and phosphoenolpyruvate carboxylase (PEPCase), ABA and ZT concentrations of flag leaves at flowering and filling stages had a significant contribution to yield formation under 6-BA and shade treatments. Overall, cytokinin regulates the inhibitory effects of shade stress on wheat photosynthesis, antioxidant capacity and hormone homeostasis to reduce wheat yield loss.

    Keywords: walnut-wheat intercropping, 6-Benzyladenine, hormone, wheat yield, physiological mechanism

    Received: 18 Sep 2024; Accepted: 31 Oct 2024.

    Copyright: © 2024 Zhang, Li, Xu, Chen, Nie, Lei and Duan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Yongqiang Zhang, College of Agronomy and Biotechnology, China Agricultural University, Beijing, Beijing Municipality, China
    Juan Li, Xinjiang Academy of Agricultural Sciences, Urumqi, China
    Qijiang Xu, Xinjiang Academy of Agricultural Sciences, Urumqi, China
    Chuanxin Chen, Xinjiang Academy of Agricultural Sciences, Urumqi, China
    Shihui Nie, Xinjiang Academy of Agricultural Sciences, Urumqi, China
    Junjie Lei, Xinjiang Academy of Agricultural Sciences, Urumqi, China
    Liusheng Duan, College of Agronomy and Biotechnology, China Agricultural University, Beijing, Beijing Municipality, China

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