Oliveira Mariane de Souza, Rocha Sâmara Vieira, Schneider Vanessa Karine, Henrique-Silva Flavio, Soares Marcio Roberto, Soares-Costa Andrea
Department of Genetics and Evolution, Federal University of São Carlos, São Carlos, SP, Brazil.
Department of Natural Resources and Environmental Protection/Agrarian Sciences Center, Federal University of São Carlos, Araras, SP, Brazil.
PeerJ. 2021 Jun 28;9:e11461. doi: 10.7717/peerj.11461. eCollection 2021.
Sugarcane is a crop of global importance and has been expanding to areas with soils containing high levels of exchangeable aluminum (Al), which is a limiting factor for crop development in acidic soils. The study of the sugarcane physiological and nutritional behavior together with patterns of gene expression in response to Al stress may provide a basis for effective strategies to increase crop productivity in acidic soils.
Sugarcane cultivars were evaluated for physiological parameters (photosynthesis, stomatal conductance, and transpiration), nutrient (N, P, K, Ca, Mg, and S) and Al contents in leaves and roots and gene expression, of the genes , by qPCR, both related to the production of organic acids, and , related to oxidative stress.
Brazilian sugarcane RB867515, RB928064, and RB935744 cultivars exhibited very different responses to induced stress by Al. Exposure to Al caused up-regulation ( and ) or down-regulation (, , and ), depending on the cultivar, Al level, and plant tissue. The RB867515 cultivar was the most Al-tolerant, showing no decline of nutrient content in plant tissue, photosynthesis, transpiration, and stomatal conductance after exposure to Al; it exhibited the highest Al content in the roots, and showed important and gene expression in the roots. RB928064 only showed low expression of in roots and leaves, while RB935744 showed important expression of the gene only in the leaves. Sugarcane cultivars were classified in the following descending Al-tolerance order: RB867515 > RB928064 = RB935744. These results may contribute to the obtention of Al-tolerant cultivars that can play their genetic potential in soils of low fertility and with low demand for agricultural inputs; the selection of potential plants for breeding programs; the elucidation of Al detoxification mechanisms employed by sugarcane cultivars.
甘蔗是一种具有全球重要性的作物，并且一直在向土壤中可交换铝（Al）含量高的地区扩展，而可交换铝是酸性土壤中作物生长的限制因素。研究甘蔗的生理和营养行为以及响应铝胁迫的基因表达模式，可能为提高酸性土壤中作物生产力的有效策略提供依据。
通过qPCR评估甘蔗品种的生理参数（光合作用、气孔导度和蒸腾作用）、叶片和根系中的养分（N、P、K、Ca、Mg和S）及铝含量以及与有机酸产生相关的基因 和与氧化应激相关的基因 的表达。
巴西甘蔗品种RB867515、RB928064和RB935744对铝诱导的胁迫表现出非常不同的反应。根据品种、铝水平和植物组织的不同，暴露于铝会导致基因上调（ 和 ）或下调（ 、 和 ）。RB867515品种对铝的耐受性最强，暴露于铝后植物组织中的养分含量、光合作用、蒸腾作用和气孔导度均未下降；其根系中的铝含量最高，并且在根系中显示出重要的 和 基因表达。RB928064仅在根和叶中显示出 的低表达，而RB935744仅在叶中显示出 基因的重要表达。甘蔗品种按耐铝性从高到低排序如下：RB867515 > RB928064 = RB935744。这些结果可能有助于获得能够在低肥力且对农业投入需求低的土壤中发挥其遗传潜力的耐铝品种；为育种计划选择潜在植株；阐明甘蔗品种采用的铝解毒机制。
