The expansion of land use for agricultural interests and the excessive use of herbicides are among the causes of biodiversity losses in the Brazilian Cerrado biome. Therefore, we aimed to test the hypothesis that Dipteryx alata Vogel, a common species in this biome, is sensitive to nicosulfuron because of its high phytotoxicity. We evaluated physiological, biochemical and morphological responses in D. alata plants exposed to increasing doses of the herbicide. Young plants were transplanted to 10 L pots containing substrate composed of soil and sand (2:1) after fertilization. After an acclimation period, the following doses of nicosulfuron were applied: 0 (control), 6, 12, 24, 48, and 60 g a.e. ha-1. The experiment was conducted in a randomized block design factorial scheme with six doses of nicosulfuron, three evaluation times, and five replicates per treatment. The effects of the herbicide were assessed by measuring gas exchange, chlorophyll a fluorescence, photosynthetic pigments, membrane permeability, antioxidant enzymes and acetolactate synthase. Nicosulfuron altered the photosynthetic machinery and enzymatic metabolism of D. alata. Reductions in physiological traits, increased catalase and ascorbate peroxidase activities, enhanced malondialdehyde concentrations rate of electrolyte leakage and decreased acetolactate synthase activity in response to nicosulfuron all suggest that D. alata is sensitive to this herbicide.

中文翻译：

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Dipteryx alata是巴西Cerrado的原生树，对除草剂烟嘧磺隆敏感。

为农业利益而扩大土地利用和过度使用除草剂是巴西塞拉多生物群落生物多样性丧失的原因之一。因此，我们旨在检验这一生物群落中常见的物种Dipteryx alata Vogel对烟嘧磺隆敏感的假设，因为它具有很高的植物毒性。我们评估了暴露于除草剂剂量增加的D. alata植物的生理，生化和形态反应。受精后，将幼小植物移植到10 L的盆中，该盆包含由土壤和沙子构成的基质（2：1）。适应期后，施用下列剂量的烟嘧磺隆：0（对照），6、12、24、48和60 g ae ha-1。该实验是在随机区组设计因子方案中进行的，其中包含六剂烟嘧磺隆，三个评估时间，每次处理重复五次。通过测量气体交换，叶绿素a荧光，光合色素，膜通透性，抗氧化酶和乙酰​​乳酸合酶来评估除草剂的作用。烟嘧磺隆改变了D. alata的光合作用机制和酶促代谢。生理特性的降低，过氧化氢酶和抗坏血酸过氧化物酶活性的增加，丙二醛浓度增加的电解质渗漏速率和对烟嘧磺隆的响应降低的乙酰乳酸合酶活性均表明，D。alata对这种除草剂敏感。烟嘧磺隆改变了D. alata的光合作用机制和酶促代谢。生理特性的降低，过氧化氢酶和抗坏血酸过氧化物酶活性的增加，丙二醛浓度增加的电解质渗漏速率和对烟嘧磺隆的响应降低的乙酰乳酸合酶活性均表明，D。alata对这种除草剂敏感。烟嘧磺隆改变了D. alata的光合作用机制和酶促代谢。生理特性的降低，过氧化氢酶和抗坏血酸过氧化物酶活性的增加，丙二醛浓度增加的电解质渗漏速率和对烟嘧磺隆的响应降低的乙酰乳酸合酶活性均表明，D。alata对这种除草剂敏感。