Department of Biotechnology, College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, China.
Department of Agronomy, College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, China.
Int J Mol Sci. 2024 May 14;25(10):5341. doi: 10.3390/ijms25105341.
Manganese (Mn) is a heavy metal that can cause excessive Mn poisoning in plants, disrupting microstructural homeostasis and impairing growth and development. However, the specific response mechanisms of leaves to Mn poisoning have not been fully elucidated. This study revealed that Mn poisoning of soybean plants resulted in yellowing of old leaves. Physiological assessments of these old leaves revealed significant increases in the antioxidant enzymes activities (peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)) and elevated levels of malondialdehyde (MDA), proline, indoleacetic acid (IAA), and salicylic acid (SA), under 100 μM Mn toxicity. Conversely, the levels of abscisic acid (ABA), gibberellin 3 (GA), and jasmonic acid (JA) significantly decreased. The Mn content in the affected leaves significantly increased, while the levels of Ca, Na, K, and Cu decreased. Transcriptome analysis revealed 2258 differentially expressed genes in the Mn-stressed leaves, 744 of which were upregulated and 1514 were downregulated; these genes included genes associated with ion transporters, hormone synthesis, and various enzymes. Quantitative RT-PCR (qRT-PCR) verification of fifteen genes confirmed altered gene expression in the Mn-stressed leaves. These findings suggest a complex gene regulatory mechanism under Mn toxicity and stress, providing a foundation for further exploration of Mn tolerance-related gene regulatory mechanisms in soybean leaves. Using the methods described above, this study will investigate the molecular mechanism of old soybean leaves' response to Mn poisoning, identify key genes that play regulatory roles in Mn toxicity stress, and lay the groundwork for cultivating high-quality soybean varieties with Mn toxicity tolerance traits.
锰（Mn）是一种重金属，它会导致植物中锰中毒过量，破坏微结构的内稳态并损害生长和发育。然而，叶片对锰中毒的具体响应机制尚未完全阐明。本研究表明，大豆植株的锰中毒会导致老叶变黄。对这些老叶进行的生理评估表明，在 100 μM Mn 毒性下，抗氧化酶活性（过氧化物酶（POD）、超氧化物歧化酶（SOD）、抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT））显著增加，丙二醛（MDA）、脯氨酸、吲哚乙酸（IAA）和水杨酸（SA）水平升高。相反，脱落酸（ABA）、赤霉素 3（GA）和茉莉酸（JA）的水平显著降低。受影响叶片中的 Mn 含量显著增加，而 Ca、Na、K 和 Cu 的水平降低。转录组分析显示，在 Mn 胁迫叶片中有 2258 个差异表达基因，其中 744 个上调，1514 个下调；这些基因包括与离子转运体、激素合成和各种酶相关的基因。对十五个基因的定量 RT-PCR（qRT-PCR）验证证实了 Mn 胁迫叶片中基因表达的改变。这些发现表明，在 Mn 毒性和胁迫下存在复杂的基因调控机制，为进一步探索大豆叶片中 Mn 耐受相关基因调控机制提供了基础。本研究将采用上述方法，研究老大豆叶片对 Mn 中毒的响应分子机制，鉴定在 Mn 毒性胁迫中起调节作用的关键基因，并为培育具有 Mn 毒性耐受特性的优质大豆品种奠定基础。
