Zhang Zhe, Ma Rongrong, Tao Yihui, Wang Ziling, Yang Yingli
College of Life Science, Northwest Normal University, Lanzhou, 730070, PR China.
BMC Plant Biol. 2025 Apr 4;25(1):430. doi: 10.1186/s12870-025-06446-5.
Seed germination represents a pivotal phase in crop production, exhibiting pronounced sensitivity to abiotic stresses. In this study, wheat seeds of the 'Ningchun 4' variety were subjected to treatments involving zinc (Zn) chloride and iron (Fe) chloride, both individually and in combination. The impacts of these treatments on Fe and Zn accumulation, starch mobilization, antioxidant responses, and nitric oxide (NO) metabolism during seed germination were thoroughly examined. Individual application of Fe or Zn significantly inhibited and delayed wheat seed germination, which was accompanied by elevated levels of starch, sucrose, and soluble sugars, as well as increased reactive oxygen species and malondialdehyde concentrations. Concurrently, total amylase and α-amylase activities were downregulated, while antioxidant enzyme activities and the expression of TaCAT, TaAPX, and TaGR were upregulated. Seeds treated solely with Fe exhibited excessive Fe accumulation, heightened Fe content, and diminished Zn content. Conversely, these trends were reversed in seeds treated with Zn alone. Furthermore, reduced NO levels were associated with downregulated nitrate reductase and nitric oxide synthase activities, alongside decreased expression of their corresponding genes in response to Fe exposure. Notably, the above effects induced by Zn alone were less severe compared to those induced by Fe stress. Importantly, the addition of Zn (100 µM or 250 µM) significantly alleviated the detrimental effects of Fe on several parameters in germinating seeds. The results from NO fluorescent probe staining corroborated the quantitative NO measurements across different treatments. In conclusion, an appropriate concentration of Zn effectively promoted the germination of Fe-stressed wheat seeds by mitigating Fe accumulation, attenuating oxidative damage, and enhancing starch mobilization during seed germination.
种子萌发是作物生产中的一个关键阶段，对非生物胁迫表现出明显的敏感性。在本研究中，对‘宁春4号’小麦种子进行了单独或组合使用氯化锌（Zn）和氯化铁（Fe）的处理。全面研究了这些处理对种子萌发过程中铁和锌积累、淀粉动员、抗氧化反应以及一氧化氮（NO）代谢的影响。单独施用铁或锌显著抑制并延迟了小麦种子萌发，同时伴随着淀粉、蔗糖和可溶性糖水平的升高，以及活性氧和丙二醛浓度的增加。与此同时，总淀粉酶和α -淀粉酶活性下调，而抗氧化酶活性以及TaCAT、TaAPX和TaGR的表达上调。仅用铁处理的种子表现出铁积累过多、铁含量升高和锌含量降低。相反，单独用锌处理的种子则出现相反的趋势。此外，较低的NO水平与硝酸还原酶和一氧化氮合酶活性下调以及相应基因的表达降低有关，这是对铁暴露的响应。值得注意的是，单独锌诱导的上述影响与铁胁迫相比不太严重。重要的是，添加锌（100 µM或250 µM）显著减轻了铁对萌发种子中几个参数的有害影响。NO荧光探针染色结果证实了不同处理下NO的定量测量。总之，适当浓度的锌通过减轻铁积累、减轻氧化损伤和增强种子萌发过程中的淀粉动员，有效促进了铁胁迫小麦种子的萌发。
