Tao Yuzhao, Liu Changzhuang, Piao Lin, Yang Fuqiang, Liu Jiaqi, Jan Muhammad Faheem, Li Ming
College of Agriculture, Northeast Agricultural University, Harbin 150030, China.
Maize Research Institute, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China.
Plants (Basel). 2023 Mar 22;12(6):1407. doi: 10.3390/plants12061407.
Manganese deficiency critically impairs the function and stability of photosystem II (PSII) and negatively impacts crop growth and yield. However, the response mechanisms of carbon and nitrogen metabolism to Mn deficiency in different genotypes of maize and the differences in Mn deficiency tolerance are unclear. Herein, three different genotypes of maize seedlings (sensitive genotype: Mo17, tolerant genotype: B73, and B73 × Mo17) were exposed to Mn deficiency treatment for 16 days using liquid culture with different concentrations of MnSO [0.00, 2.23, 11.65, and 22.30 mg/L (control)]. We found that complete Mn deficiency significantly reduced maize seedling biomass; negatively affected the photosynthetic and chlorophyll fluorescence parameters; and depressed nitrate reductase, glutamine synthetase, and glutamate synthase activity. This resulted in reduced leaf and root nitrogen uptake, with Mo17 being most severely inhibited. B73 and B73 × Mo17 maintained higher sucrose phosphate synthase and sucrose synthase activities and lower neutral convertase activity compared to Mo17, which resulted in higher accumulation of soluble sugars and sucrose and maintenance of the osmoregulation capacity of leaves, which helped mitigate damage caused by Mn deficiency. The findings revealed the physiological regulation mechanism of carbon and nitrogen metabolism in different genotypes of maize seedlings that resist Mn deficiency stress, providing a theoretical basis for developing high yield and quality.
锰缺乏严重损害光系统II（PSII）的功能和稳定性，并对作物生长和产量产生负面影响。然而，不同基因型玉米中碳氮代谢对锰缺乏的响应机制以及耐锰缺乏性的差异尚不清楚。在此，采用不同浓度的硫酸锰[0.00、2.23、11.65和22.30 mg/L（对照）]液体培养，对三种不同基因型的玉米幼苗（敏感基因型：Mo17、耐基因型：B73以及B73×Mo17）进行16天的缺锰处理。我们发现，完全缺锰显著降低了玉米幼苗生物量；对光合和叶绿素荧光参数产生负面影响；并抑制了硝酸还原酶、谷氨酰胺合成酶和谷氨酸合成酶的活性。这导致叶片和根系氮吸收减少，其中Mo17受到的抑制最为严重。与Mo17相比，B73和B73×Mo17保持了较高的蔗糖磷酸合成酶和蔗糖合成酶活性以及较低的中性转化酶活性，这导致可溶性糖和蔗糖积累增加，并维持了叶片的渗透调节能力，有助于减轻缺锰造成的损害。这些发现揭示了不同基因型玉米幼苗抵抗缺锰胁迫时碳氮代谢的生理调节机制，为培育高产优质品种提供了理论依据。
