Department of Botany and Microbiology, Faculty of Science, Cairo University, Giza, 12613, Egypt.
Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium; Centre of Excellence Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Antwerp, Belgium.
J Plant Physiol. 2020 Jul;250:153184. doi: 10.1016/j.jplph.2020.153184. Epub 2020 May 11.
Although it is well known that parasitic weeds such as Orobanche (broomrape) significantly reduce the yield of economically important crops, their infection-induced oxidative changes need more exploration in their host plants. Moreover, applying an eco-friendly approach to minimize the infection is not yet available. This study was conducted to understand the effect of Orobanche ramosa infection on oxidative and redox status of tomato plants and the impact of hormonal (indole acetic acid (IAA); 0.09 mM and salicylic acid (SA); 1.0 mM) seed-priming upon mitigating the infection threats. Although Orobanche invades tomato roots, its inhibitory effects on shoot biomass were also indicted. Orobanche infection usually induces oxidative damage i.e., high lipid peroxidation, lipoxygenase activity and HO levels, particularly for roots. Interestingly, hormonal seed-priming significantly enhanced tomato shoots and roots growth under both healthy and infected conditions. Also, IAA and SA treatment significantly reduced Orobanche infection-induced oxidative damage. The protective effect of seed-priming was explained by increasing the antioxidant defense markers including the antioxidant metabolites (i.e., total antioxidant capacity, carotenoids, phenolics, flavonoids, ASC, GSH, tocopherols) and enzymes (CAT, POX, GPX, SOD, GR, APX, MDHAR, DHAR), particularly in infected tomato seedlings. Additionally, cluster analysis indicated the differential impact of IAA- and SA-seed-priming, whereas lower oxidative damage and higher antioxidant enzymes' activities in tomato root were particularly reported for IAA treatment. The principal component analysis (PCA) also proclaimed an organ specificity depending on their response to Orobanche infection. Collectively, here and for the first time, we shed the light on the potential of seed-priming with either IAA or SA to mitigate the adverse effect of O. ramosa stress in tomato plants, especially at oxidative stress levels.
虽然众所周知，寄生杂草如列当（列当）会显著降低经济重要作物的产量，但它们在宿主植物中引起的感染诱导的氧化变化需要更多的探索。此外，应用环保方法来最小化感染还不可用。本研究旨在了解列当 ramosa 感染对番茄植株氧化和氧化还原状态的影响，以及激素（吲哚乙酸（IAA）；0.09 mM 和水杨酸（SA）；1.0 mM）种子引发对减轻感染威胁的影响。尽管列当侵入番茄根系，但它对地上部分生物量的抑制作用也表明。列当感染通常会引起氧化损伤，即高脂质过氧化、脂氧合酶活性和 HO 水平，特别是对根。有趣的是，激素种子引发在健康和感染条件下都显著增强了番茄地上部分和根系的生长。此外，IAA 和 SA 处理显著降低了列当感染诱导的氧化损伤。种子引发的保护作用可以通过增加抗氧化防御标志物来解释，包括抗氧化代谢物（即总抗氧化能力、类胡萝卜素、酚类、类黄酮、ASC、GSH、生育酚）和酶（CAT、POX、GPX、SOD、GR、APX、MDHAR、DHAR），特别是在感染的番茄幼苗中。此外，聚类分析表明 IAA 和 SA 种子引发的影响存在差异，而在番茄根中，IAA 处理的氧化损伤较低，抗氧化酶活性较高。主成分分析（PCA）也宣称了一种器官特异性，这取决于它们对列当感染的反应。总的来说，在这里，我们首次揭示了 IAA 或 SA 种子引发在减轻番茄植物列当胁迫的不利影响方面的潜力，特别是在氧化应激水平方面。
