Duan Mingzheng, Bao Liuyuan, Eman Momina, Han Duo, Zhang Yongzhi, Zheng Bingsong, Yang Shunqiang, Rao Muhammad Junaid
College of Agronomy and Life Sciences, Zhaotong University, Zhaotong 657000, China.
State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou 311300, China.
Plants (Basel). 2024 Sep 25;13(19):2692. doi: 10.3390/plants13192692.
The Defective in Induced Resistance 1 () gene, a member of the lipid transferase proteins (LTPs), plays a crucial role in plant defense against pathogens. While previous transcriptomic studies have highlighted the significant expression of citrus LTPs during biotic stress, functional annotations of LTPs in the genera remain limited. In this study, we cloned the ( gene and overexpressed it in to evaluate its stress response mechanisms against biotic stress. The transgenic lines showed fewer disease symptoms in response to ( DC3000) compared to wild-type . Defense and pathogenesis-responsive genes such as , , , and were significantly induced, showing a 2- to 12-fold increase in all transgenic lines compared to the wild type. In addition, the DC3000-infected transgenic lines demonstrated elevated levels of flavonoids and salicylic acid (SA), along with higher expression of SA-related genes, compared to the wild type. Moreover, all transgenic lines possessed lower reactive oxygen species levels and higher activity of antioxidant defense enzymes such as superoxide dismutase, peroxidase, and catalase under DC3000 stress compared to the wild type. The up-regulation of defense genes, activation of the SA pathway, accumulation of flavonoids, and reinforcement of antioxidant defense mechanisms in transgenic lines in response to DC3000 underscore the critical role of in fortifying plant immunity. Thus, constitutes a promising candidate gene for improving bacterial disease resistance in commercial citrus cultivars.
诱导抗性缺陷1（）基因是脂质转移蛋白（LTPs）家族的成员，在植物抵御病原体的过程中发挥着关键作用。虽然先前的转录组学研究强调了柑橘LTPs在生物胁迫期间的显著表达，但该属中LTPs的功能注释仍然有限。在本研究中，我们克隆了（基因并在中过表达，以评估其对生物胁迫的应激反应机制。与野生型相比，转基因品系对（DC3000）的病害症状更少。防御和病程响应基因如、、和被显著诱导，与野生型相比，所有转基因品系中的表达增加了2至12倍。此外，与野生型相比，感染DC3000的转基因品系中黄酮类化合物和水杨酸（SA）水平升高，同时SA相关基因的表达也更高。此外，在DC3000胁迫下，所有转基因品系的活性氧水平较低，超氧化物歧化酶、过氧化物酶和过氧化氢酶等抗氧化防御酶的活性较高。转基因品系中防御基因的上调、SA途径的激活、黄酮类化合物的积累以及抗氧化防御机制的加强，突出了在增强植物免疫力方面的关键作用。因此，是提高商业柑橘品种对细菌病害抗性的一个有潜力的候选基因。
