Santos Luiz C N Dos, Gaion Lucas A, Prado Renato M, Barreto Rafael F, Carvalho RogÉrio F
Universidade Estadual Paulista (UNESP), Departamento de Solos e Adubos, Faculdade de Ciências Agrárias e Veterinária, Via de Acesso Prof. Paulo Donato Castellane, s/n, Zona Rural, 14884-900 Jaboticabal, SP, Brazil.
Universidade de Marília, Centro de Ciências Agrárias, Avenida Higino Muzzy Filho, 1001, Cidade Universitária, 17525-902 Marília, SP, Brazil.
An Acad Bras Cienc. 2020 Nov 11;92(3):e20190254. doi: 10.1590/0001-3765202020190254. eCollection 2020.
Plant responses to nitrogen supply are dependent on auxin signaling, but much still remains to be elucidated regarding N deficiency in tomato. Thus, the objective of this work was to evaluate how low auxin sensitivity regulates the responses of tomato plants to N deficiency. For this purpose, we used the tomato diageotropica mutant, with low auxin sensitivity, and a near isogenic line cv. Micro-Tom grown in nutrient solutions under absence and presence of nitrogen. Plant height, stem diameter, root and shoot dry mass, area and root density, number of lateral roots, leaf area, chlorophylls and carotenoids content, nitrogen accumulation and nitrogen use efficiency were evaluated. We observed a clear interaction between the tomato genotype and nitrogen. When the plants were grown with nitrogen, 'Micro-Tom' showed higher growth than the diageotropica mutant. Under nitrogen deficiency condition, the mutant showed improved growth, nitrogen use efficiency and higher contents of pigments. In general, the low sensitivity to auxin in diageotropica caused reduced growth in both shoot and root. However, the diageotropica tomato showed a positive regulation of the nitrogen use efficiency under nitrogen deficiency. In general, our data revealed that the reduced sensitivity to auxin increased the adaptive capacity to the nitrogen deficiency.
植物对氮素供应的响应依赖于生长素信号传导，但关于番茄氮素缺乏仍有许多有待阐明的地方。因此，本研究的目的是评估低生长素敏感性如何调节番茄植株对氮素缺乏的响应。为此，我们使用了生长素敏感性低的番茄双定向突变体和一个近等基因系品种Micro-Tom，它们在有无氮素的营养液中生长。对株高、茎直径、根和地上部干质量、面积和根密度、侧根数、叶面积、叶绿素和类胡萝卜素含量、氮素积累和氮素利用效率进行了评估。我们观察到番茄基因型与氮素之间存在明显的相互作用。当植株在有氮条件下生长时，“Micro-Tom”的生长高于双定向突变体。在氮素缺乏条件下，突变体的生长、氮素利用效率提高，色素含量增加。总体而言，双定向突变体中对生长素的低敏感性导致地上部和根部生长均减少。然而，双定向番茄在氮素缺乏条件下对氮素利用效率有正向调节作用。总体而言，我们的数据表明，对生长素的敏感性降低增加了对氮素缺乏的适应能力。
