Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (2): 639-647.DOI: 10.1016/j.jia.2024.08.002

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高温条件下同化物供应对玉米籽粒淀粉合成的影响

  

  • 收稿日期:2024-03-23 修回日期:2024-08-05 接受日期:2024-06-24 出版日期:2026-02-20 发布日期:2026-01-06
  • 基金资助:

Effects of changing assimilate supply on starch synthesis in maize kernels under high temperature stress

Teng Li1, 2, Shumei Wang1, Qing Liu1, Xuepeng Zhang3, Lin Chen1, Yuanquan Chen1, Wangsheng Gao1, 4#, Peng Sui1, 2#   

  1. 1 College of Agronomy and Biotechnology, China Agricultural University/Key Laboratory of Farming System, Ministry of Agriculture and Rural Affairs, Beijing 100193, China

    2 Innovation Center of Agricultural Technology for Lowland Plain of Hebei, Wuqiao 061802, China

    3 Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China

    4 National Academy of Agricultural Science and Technology Strategy, China Agricultural University, Beijing 100193, China

  • Received:2024-03-23 Revised:2024-08-05 Accepted:2024-06-24 Online:2026-02-20 Published:2026-01-06
  • About author:#Correspondence Peng Sui, E-mail: suipeng@cau.edu.cn; Wangsheng Gao, E-mail: gaows@cau.edu.cn
  • Supported by:
    The authors want to thank the staff of Wuqiao Experimental Station of China Agricultural University for their excellent work.  This research was financially supported by the National Natural Science Foundation of China (32071978) and the National Key Research and Development Program of China (2022YFD2300901 and 2022YFD2300905).

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摘要：

高温胁迫通过减少籽粒中的淀粉积累来显着降低玉米产量。但是，高温通过减少同化物的供应还是直接影响籽粒中淀粉的合成，从而降低产量，仍然是有争议的。为了阐明潜在的机制，在玉米籽粒建成期，采用热敏感型玉米品种先玉335（XY），设置30/20°C（最高/最低温度，对照）和40/30°C两组为期7天的温度处理。采用籽粒同步授粉（SP），顶部籽粒授粉（AP）和遮荫处理来改变玉米中固有的源-库比例。结果表明，在SP处理中，相比30℃处理，顶部籽粒的重量在40°C以下降低了11.9％；在40℃下，13C含量，细胞壁转化酶（CWIN）的活性也分别减少了15.9％，36.7％和16.4％。在遮荫处理中，由于同化物供应量的减少，40/30°C导致13C含量、淀粉积累和CWIN活性降低的程度甚至更高。相反，在AP处理中，淀粉含量和CWIN在40/30°C下增加了22.0和18.5％，籽粒重量和13C含量与SP处理相差不大。与AP处理中的顶部籽粒一致，高温处理对SP和遮荫处理中的中部籽粒没有负面影响，在高温处理下，中部籽粒重量和淀粉含量并未降低。所有籽粒都处在相同的环境中，但它们对高温的反应不同。在顶部籽粒中，原本在高温下受抑制的淀粉合成可以通过AP处理增加碳供应来挽救。在高温条件下，中部籽粒、AP处理下的顶部籽粒与SP和遮荫处理下的籽粒应对高温的反应证明同化物供应降低是高温引起籽粒内淀粉合成减少的首要因素。我们的发现为进一步研究高温诱导籽粒败育提供了一个理论基础。

Abstract:

High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.  However, the mechanism by which HT affects starch synthesis remains controversial - whether through reduced assimilate supply or direct inhibition on kernel metabolism.  To clarify these mechanisms, a heat-sensitive maize hybrid, Xianyu 335 (XY), was exposed to 30°C/20°C (maximum/minimum temperature, control) and 40°C/30°C for seven consecutive days during the seed setting stage.  Synchronous pollination (SP), apical pollination (AP), and shading treatments were applied to manipulate the inherent source–sink ratio in maize plants.  Results showed that apical kernel weight decreased by 11.9% under 40°C in the SP treatment.  The 13C content, starch accumulation, and cell-wall invertase (CWIN) activity also declined by 15.9, 36.7, and 16.4%, respectively, under HT.  In the shading treatment, 40°C/30°C caused even greater reductions in 13C content, starch accumulation, and CWIN activity due to diminished assimilate supply.  Conversely, in the AP treatment, starch content and CWIN activity increased by 22.0 and 18.5%, respectively, under 40°C/30°C, resulting in kernel weight and 13C content similar to those in SP and shading treatments regardless of temperature.  Consistent with apical kernels under AP, HT did not negatively affect middle kernels in either SP or shading treatments, as kernel weight and starch content remained unchanged under HT.  Although all kernels were exposed to the same HT or control environment, their responses varied a lot.  The impaired starch synthesis in apical kernels under HT was rescued by increasing carbon supply via AP treatment.  The contrasting performance among middle kernels, apical kernels under AP, and apical kernels under SP or shading indicates that reduced carbon supply is a critical factor underlying inhibited starch accumulation.  Our findings provide a theoretical basis for further understanding kernel abortion under HT.

Key words: high temperature stress , maize ,  seed setting stage ,  cell wall invertase ,  starch synthesis