Impact of heat stress on the development, physiological and biochemical characteristics of Tartary buckwheat flowers, and its transcriptomic analysis

Lisong Liu; Li Li; Yanjun Feng; Tao Wang; Chenglei Li; Huala Wu; Yufeng Hu; Qi Wu; Haixia Zhao

doi:10.1016/j.plaphy.2025.109535

Impact of heat stress on the development, physiological and biochemical characteristics of Tartary buckwheat flowers, and its transcriptomic analysis

Plant Physiol Biochem. 2025 Jan 22:220:109535. doi: 10.1016/j.plaphy.2025.109535. Online ahead of print.

Authors

Lisong Liu¹, Li Li¹, Yanjun Feng¹, Tao Wang¹, Chenglei Li¹, Huala Wu¹, Yufeng Hu², Qi Wu¹, Haixia Zhao³

Affiliations

¹ College of Life Science, Sichuan Agricultural University, Ya'an, 625014, China.
² State Key Laboratory of Crop Exploration and Utilization in Southwest China, Sichuan Agricultural University, Ya'an, 611130, China.
³ College of Life Science, Sichuan Agricultural University, Ya'an, 625014, China. Electronic address: zhaohaixia@sicau.edu.cn.

PMID: 39864295
DOI: 10.1016/j.plaphy.2025.109535

Abstract

Tartary buckwheat (Fagopyrum tataricum), a functional grain known for its medicinal and nutritional properties, has garnered significant attention due to its high flavonoid content and unique health benefits. Heat stress during the flowering stage can lead to sterility in Tartary buckwheat, resulting in reduced yields. This study investigates the effects of a treatment (30/27 °C for 7 days) on flower development, fertility, stress physiology, and gene expression in Tartary buckwheat, while also validating the efficacy of hormone treatments in alleviating the negative effects of heat stress. The results show that fertilization in Tartary buckwheat typically occurs within 3-5 days post-anthesis. By the 5th day, the stamen length in the heat-treated group was reduced by 13.89% compared to the control, while pistil length increased by 35.44%. Heat stress delayed the pistil stigma's transition into its highly receptive phase and caused a significant reduction in pollen viability by 15.25% after 5 days of treatment. Furthermore, after 7 days of treatment, the levels of H₂O₂ and O₂^- increased by 44.9% and 37.2%, respectively. However, Tartary buckwheat mitigated the impact of oxidative damage by enhancing the enzymatic activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Transcriptome analysis revealed that heat stress significantly suppressed the expression of genes in hormone signaling pathways, such as indole-3-acetic acid (IAA), gibberellin (GA), and jasmonic acid (JA). Under heat treatment conditions, exogenous hormone application significantly regulated the dynamics of flower development. Specifically, after 3 days of heat treatment, all hormone treatments significantly inhibited the abnormal elongation of stamens, with GA notably suppressing the abnormal elongation of pistils. After 5 days, GA significantly promoted stamen elongation, while IAA and jasmonic acid (JA) significantly inhibited the abnormal elongation of pistils. After 7 days, all three hormone treatments significantly promoted stamen elongation and effectively inhibited abnormal pistil growth. These results suggest that under heat stress conditions, GA plays a key role in promoting stamen elongation, while IAA and JA inhibit the abnormal elongation of the pistil. Prolonged high temperatures can impair the function of floral organs, while JA treatment on the seventh day of heat treatment effectively restored pistil receptivity and significantly improved pollen vitality. In summary, this study provides in-depth insights into the mechanisms by which heat stress affects flower development in Tartary buckwheat, offering theoretical foundations and practical guidance for reducing the impact of heat stress on buckwheat yield.

Keywords: Heat stress; Hormone; Pollen viability; Stigma receptivity; Tartary buckwheat.