Yoshida Camila Hatsu Pereira, Pacheco Ana Claudia, de Marcos Lapaz Allan, de Souza Ferreira Clayton, Dal-Bianco Maximiller, Viana José Marcelo Soriano, Ribeiro Cleberson
Departamento de Agronomia, Universidade do Oeste Paulista, Presidente Prudente, São Paulo, 19067-175, Brazil.
Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil.
Planta. 2023 Jan 2;257(2):28. doi: 10.1007/s00425-022-04062-3.
Inbred line 11-133 of popcorn showed the lowest apoplast Al and total Al concentrations and Al-lumogallion complex, associated with a more efficient antioxidant system, mainly due to glutathione metabolism. Popcorn (Zea mays L. var. everta) is largely intended for human consumption. About 40% of the world's arable soils are acidic. In soils acidic, aluminum (Al) ionizes producing the trivalent cation, which is highly toxic to plants. Hence, this work aimed to: (1) evaluate the Al toxicity sites and its effect on the structure of the root tips, (2) quantify Al concentrations in the apoplast and symplast of the roots, and (3) to elucidate the modulation on the activity of antioxidant enzymes and metabolites of the ascorbate-glutathione cycle in two popcorn inbred lines (ILs) 11-133 and 11-60, classified as tolerant and sensitive to this metal, respectively. Aluminum toxicity did not affect the shoot growth; however, there was a yellowing of the oldest leaf blade only in 11-60. The better performance of 11-133 is related to lower apoplastic and total Al concentrations and Al accumulation in the root associated with a lower fluorescence of Al-lumogallion complex at the root tip, indicating the presence of mechanisms of chelation with this metal. Consequently, this IL showed less change in root morphoanatomy and lower reactive oxygen species and malondialdehyde content, which are associated with a more efficient enzymatic and non-enzymatic system, mainly due to the higher content of the glutathione metabolite and the higher activities of superoxide dismutase, monodehydroascorbate reductase, dehydroascorbate reductase, γ-glutamylcysteine synthetase, and glutathione peroxidase enzymes. Thus, these findings illustrated above indicate how internal mechanisms of detoxification respond to Al in popcorn, which can be used as tolerance biomarkers.
爆裂玉米自交系11 - 133的质外体铝和总铝浓度以及铝 - 荧光镓络合物含量最低，这与更有效的抗氧化系统有关，主要归因于谷胱甘肽代谢。爆裂玉米（Zea mays L. var. everta）主要供人类食用。世界上约40%的耕地土壤呈酸性。在酸性土壤中，铝离子化产生三价阳离子，对植物具有高毒性。因此，本研究旨在：（1）评估铝毒位点及其对根尖结构的影响；（2）量化根的质外体和共质体中的铝浓度；（3）阐明两个分别对该金属具有耐受性和敏感性的爆裂玉米自交系（ILs）11 - 133和11 - 60中抗氧化酶活性和抗坏血酸 - 谷胱甘肽循环代谢物的调节情况。铝毒并未影响地上部生长；然而，仅在11 - 60中最老的叶片出现了黄化现象。11 - 133的较好表现与较低的质外体铝和总铝浓度以及根中铝的积累有关，同时根尖处铝 - 荧光镓络合物的荧光较低，表明存在与该金属螯合的机制。因此，该自交系在根形态解剖学上的变化较小，活性氧和丙二醛含量较低，这与更有效的酶促和非酶促系统有关，主要是由于谷胱甘肽代谢物含量较高以及超氧化物歧化酶、单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶、γ - 谷氨酰半胱氨酸合成酶和谷胱甘肽过氧化物酶的活性较高。因此，上述研究结果表明了爆裂玉米中解毒的内部机制如何响应铝，这些机制可作为耐受性生物标志物。
