Journal of Integrative Agriculture

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低温敏感型小麦顶端小穗变异突变体的鉴定及遗传分析

  

  • 收稿日期:2024-12-22 修回日期:2025-03-22 接受日期:2025-01-20

Characterization and genetic identification of a low-temperature-sensitive wheat apical spike aberrance mutant

Tongzhu Wang1*, Bin Chen1*, Yaoyao Yang1*, Ziqiang Mo1, Zhaoyong Zeng2, Yanlin Liu1, Huaping Tang1, Jian Ma1#, Guangdeng Chen2#   

  1. 1 State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China/ Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, China

    2 College of Resources, Sichuan Agricultural University, Chengdu 611130, China

  • Received:2024-12-22 Revised:2025-03-22 Accepted:2025-01-20
  • About author:#Correspondence Jian Ma, E-mail: jianma@sicau.edu.cn; Guangdeng Chen, E-mail: gdchen@sicau.edu.cn * Contributed equally to this paper.
  • Supported by:

    This research was supported by the National Key R&D Program of China (2023YFD1201900), the Sichuan Province Science Foundation for Distinguished Young Scholars, China (2022JDJQ0006).  

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摘要：

穗部发育是决定小麦产量的关键因素，穗部的耐冷性对保持育性和生产力至关重要。本研究对穗部顶端畸形突变体lwasa-B1进行了全面的鉴定和分析，结果表明，lwasa-B1是一个低温敏感突变体，在15°C以下穗部发育受到明显的改变，导致其耐冷性降低。与野生型相比，低温胁迫下的lwasa-B1表现出生长延迟、分蘖增多以及小穗退化。lwasa-B1的过氧化氢酶、过氧化物酶和生长素活性显著降低，而丙二醛和赤霉素含量显著升高。利用代谢组学和转录组综合分析，推测lwasa-B1可能参与植物激素信号转导和苯丙烷类代谢调控途径。将目标基因定位于4B染色体短臂上标记k_sau_4B_17478331和k_sau_4B_19541181之间，遗传距离为2.1cM。结合BSE-Seq、转录组学和代谢组学联合分析，推测TraesCS4B02G023800是与lwasa-B1相关的潜在关键基因。本研究揭示了lwasa-B1对低温胁迫的表型和生理反应，并挖掘了一个可能调控小麦穗退化的候选基因。本研究初步解析了低温胁迫下小麦穗退化的调控机制，为小麦耐低温品种的选育提供了理解基础。

Abstract:

Spike development is a key factor in determining wheat yield, and cold tolerance during the spike’s vulnerable stages is essential for preserving both fertility and productivity.  This study presents a comprehensive characterization of the apical spike aberrance mutant lwasa-B1, which was generated through ethyl methanesulfonate mutagenesis of the wheat cultivar Chuannong 16, and its response to low-temperature stress.  The mutant lwasa-B1 exhibited reduced cold tolerance, with a critical temperature threshold identified between 13-15°C.  Under low-temperature stress, lwasa-B1 showed delayed growth, increased tillering, and varying degrees of spike degradation.  Compared to the wild type, lwasa-B1 demonstrated significantly lower enzymatic activities of catalase, peroxidase, and auxin, while levels of malondialdehyde and gibberellin were markedly higher. Integrated metabolomic and transcriptome analyses suggest that lwasa-B1 may be implicated in plant hormone signal transduction and phenylpropanoid metabolic regulation pathways.  A target gene was mapped to the chromosome arm 4BS, within a 2.07 Mb region, bounded by the markers k_sau_4B_17478331 and k_sau_4B_19541181. The integrated analysis, encompassing BSE-Seq, transcriptomics, and metabolomics, has identified TraesCS4B02G023800 as a potentially key gene associated with lwasa-B1.  This research delineates the phenotypic and physiological responses of lwasa-B1 to low-temperature stress and nominates a candidate gene potentially responsible for spike degradation.  The study provides a preliminary dissection of the regulatory mechanisms underlying spike degradation in wheat under low-temperature stress, contributing significant insights for wheat breeding programs.

Key words: wheat , spike , low-temperature , BSE-seq , linkage map