中国农业科学 ›› 2026, Vol. 59 ›› Issue (9): 1955-1974.doi: 10.3864/j.issn.0578-1752.2026.09.009

• 园艺 • 上一篇    下一篇

低磷胁迫对辣椒株型、根系构型及磷利用效率的影响

刘冬丽(), 吕魏(), 张祥, 戴雄泽, 邹学校, 徐昊()   

  1. 湖南农业大学园艺学院/园艺作物种质创新与新品种选育教育部工程研究中心, 长沙 410128
  • 收稿日期:2025-11-25 接受日期:2026-03-24 出版日期:2026-05-01 发布日期:2026-05-06
  • 通信作者:
    徐昊,E-mail:
  • 联系方式: 刘冬丽,E-mail:483882667@qq.com。吕魏,E-mail:Lvwei201706@stu.hunau.edu.cn。刘冬丽和吕魏为同等贡献作者。
  • 基金资助:
    国家重点研发计划(2024YFD2300701); 国家自然科学基金(U22A20497)

Effects of Low Phosphorus Stress on Shoot Architecture, Root System Architecture, and Phosphorus Use Efficiency in Pepper (Capsicum annuum L.)

LIU DongLi(), LÜ Wei(), ZHANG Xiang, DAI XiongZe, ZOU XueXiao, XU Hao()   

  1. College of Horticulture, Hunan Agricultural University/ Engineering Research Center for Germplasm Innovation and New Varieties Breeding of Horticultural Crops, Changsha 410128
  • Received:2025-11-25 Accepted:2026-03-24 Published:2026-05-01 Online:2026-05-06

摘要:

【目的】探究低磷胁迫对辣椒(Capsicum annuum L.)地上株型、根系构型及磷利用效率的影响,并揭示其生理与分子适应机制,阐明辣椒耐低磷调控机理,为辣椒种质改良和减磷栽培提供理论支撑。【方法】以辣椒栽培品种‘樟树港’(S8)、‘遵辣1号’(Zunla-1)、8214为试材,设置5个磷浓度梯度:缺磷(P0,0 μmol·L-1)、低磷(P20,20 μmol·L-1)、中磷(P60,60 μmol·L-1;P120,120 μmol·L-1)、正常磷(P200,200 μmol·L-1),比较辣椒的地上株型、根系构型、光合色素含量、光合特性、氮磷钾养分分配及酸性磷酸酶活性,并采用qRT-PCR技术分析株型建成及磷响应相关基因的表达。【结果】低磷胁迫显著影响了辣椒的地上株型建成,导致茎秆变细、茎节间缩短、侧芽减少和分枝伸长受阻。同时,辣椒地上部生长受抑,伴随叶片脱落,导致光合色素含量与光合性能均显著下降。在根系构型方面,低磷胁迫诱导了根系构型重塑,虽然主根长度被抑制、侧根生成减少,导致根长、根尖数、根表面积、根体积、根平均直径等指标均显著下降,但植株可能通过优化资源分配,优先将光合产物和营养物质分配至根系,使得根冠比和根冠磷分配比显著增加。品种间比较显示,Zunla-1在低磷胁迫下,其总根长、根尖数、叶绿素含量、净光合速率、叶磷含量的耐低磷系数均显著高于S8和8214,表现出较强的耐低磷能力,其耐受策略表现为通过增加侧根数量和促进根系伸长来优化根系构型,并保持较高的光合色素含量、光合效率及叶磷含量。生理与分子分析显示,辣椒的适应性响应涉及生理与分子的协同调控。一方面,低磷胁迫显著上调了磷信号与转运相关基因(CaSPX1CaSPX3CaPHT1;7)、酸性磷酸酶基因(CaPAP15CaPAP17)的表达,以增强酸性磷酸酶活性和磷利用效率;另一方面,低磷胁迫还显著上调了与根茎株型建成相关的脱落酸降解基因(CaCYP707A1)和独脚金内酯合成基因(CaCCD7CaCCD8)的表达。【结论】低磷胁迫可能通过上调独脚金内酯合成和脱落酸降解基因CaCCD7CaCCD8CaCYP707A1的表达,从而抑制辣椒地上部分枝,优化根系构型,提高根冠比,并将光合产物优先分配至根系;同时激活磷响应途径以提高酸性磷酸酶活性和磷利用效率,进而系统性地提升辣椒对低磷胁迫的适应能力。

关键词: 辣椒, 低磷胁迫, 株型, 根系构型, 磷利用效率

Abstract:

【Objective】This study aims to investigate the effects of low phosphorus (P) stress on shoot architecture, root system architecture (RSA), and phosphorus utilization efficiency (PUE) in pepper (Capsicum annuum L.), to reveal the underlying physiological and molecular adaptation mechanisms, and to elucidate the regulatory mechanism of low-P tolerance, thereby providing theoretical support for pepper germplasm improvement and phosphorus-reducing cultivation.【Method】Three pepper cultivars, Zhangshugang (S8), Zunla-1, and 8214, were subjected to five phosphorus levels: phosphorus deficiency (P0, 0 µmol·L-1), low phosphorus (P20, 20 µmol·L-1), medium phosphorus (P60, 60 µmol·L-1; P120, 120 µmol·L-1), and normal phosphorus (P200, 200 µmol·L-1). Shoot architecture, root system architecture, photosynthetic pigment content, photosynthetic characteristics, nitrogen, phosphorus, and potassium nutrient allocation, and acid phosphatase activity (Apase) were compared. Additionally, qRT-PCR was used to analyze the expression of genes related to shoot and root architecture development and phosphorus response.【Result】Low phosphorus stress (P20) significantly affected shoot architecture development in pepper, resulting in thinner stems, shortened internodes, reduced lateral buds, and inhibited branch elongation. Concurrently, the inhibited shoot growth in pepper was accompanied by leaf abscission, leading to significant decreases in photosynthetic pigment content and photosynthetic performance. Regarding RSA, low phosphorus stress induced root architectural remodeling. Although primary root length was inhibited and lateral root formation decreased, resulting in significant reductions in root length, root tip number, root surface area, root volume, and average root diameter, the plants likely optimized resource allocation by preferentially allocating photosynthates and nutrients to the roots, leading to significant increases in root-to-shoot ratio and root-to-shoot phosphorus allocation ratio. Comparative analysis among cultivars revealed that under low phosphorus stress, Zunla-1 exhibited significantly higher low-P tolerance coefficients for total root length, number of root tips, chlorophyll content, net photosynthetic rate, and leaf phosphorus content compared to Zhangshugang (S8) and 8214, indicating stronger low-P tolerance. Its tolerance strategy involved optimizing RSA by increasing lateral root number and promoting root elongation, while maintaining higher levels of photosynthetic pigments, photosynthetic efficiency, and leaf phosphorus content. Physiological and molecular analyses indicated that the adaptive response of pepper involved coordinated physiological and molecular regulation. On the one hand, low phosphorus stress significantly upregulated the expression of phosphorus signaling and transporter genes (CaSPX1, CaSPX3, CaPHT1;7) and APase (CaPAP15, CaPAP17), thereby enhancing APase and PUE. On the other hand, low phosphorus stress also significantly upregulated the expression of the abscisic acid degradation gene (CaCYP707A1) and strigolactone biosynthesis genes (CaCCD7, CaCCD8), which are associated with shoot and root architecture development.【Conclusion】Low phosphorus stress may upregulate the expression of strigolactone biosynthesis genes (CaCCD7, CaCCD8) and the abscisic acid degradation gene (CaCYP707A1), thereby inhibiting shoot branching, optimizing RSA, increasing root-to-shoot ratio, and preferentially allocating photosynthates to roots. Meanwhile, it activates the phosphorus starvation response pathway to enhance APase and PUE, thereby systematically improving the adaptability of pepper to low phosphorus stress.

Key words: pepper, low phosphorus stress, shoot architecture, root system architecture, phosphorus utilization efficiency