Infections of Xylella fastidiosa subsp pauca strain “De Donno” in Alfalfa (Medicago sativa)

Alfalfa (Medicago sativa) was inoculated with the olive-infecting strain “De Donno” isolated from a symptomatic olive in Apulia (Italy), and was demonstrated that this highly pathogenic strain causes an overactive reaction that ends up with the necrosis of the inoculated stem, a reaction that differs from the notoriously Alfalfa Dwarf disease, caused by X. fastidiosa strains isolated from grapes and almond. RNASeq analysis showed that major plant immunity pathways are activated, in particular, several Calcium transmembrane transporters and enzymes responsible of the production of Reactive Oxygen Species (ROS).

本研究以紫花苜蓿（Alfalfa，学名Medicago sativa）为实验材料，接种了从意大利普利亚大区一株表现症状的橄榄植株中分离得到的侵染橄榄的"De Donno"菌株。实验证实该高致病性菌株可引发过度免疫反应，最终导致接种茎段坏死；该反应与由葡萄和杏仁中分离得到的苛养木杆菌（X. fastidiosa）引发的众所周知的苜蓿矮化病（Alfalfa Dwarf disease）截然不同。RNA测序（RNASeq）分析结果显示，植物主要免疫通路被激活，其中包括多种钙跨膜转运蛋白以及负责产生活性氧（ROS）合成的酶类。