Expression data from Ralstonia solanacearum-inoculated tomato stem

Bacterial wilt caused by Ralstonia solanacearum is a lethal, soil-borne disease of tomato. Control of the disease with chemicals and crop rotation is insufficient, because the pathogen is particularly well adapted for surviving in the soil and rhizosphere. Therefore, cultivar resistance is the most effective means for controlling bacterial wilt, but the molecular mechanisms of resistance responses remain unclear. We used microarrays to obtain the characteristics of the gene expression changes that are induced by R. solanacearum infection in resistant cultivar LS-89 and susceptible cultivar Ponderosa. Stems of LS-89 and Ponderosa seedlings at the five to six leaf-stage were inoculated just above the cotyledon by cutting the stem to one-third of its diameter with a razor, adding 5 µl of bacterial suspension (1e+6 CFU/ml of R. solanacearum strain 8107S) or distilled water for mock inoculation to the opening, then clipping the wound site to avoid bending. Inoculated plants were grown in a growth chamber at 30ºC under 30,000 lux light intensity for 12 h/day. At 1 dpi, stems were sampled by dissecting 5 mm long sections at 5 mm below the inoculation site. For each hybridization, RNA from 15 plants was used. Three biological replicates of microarray analysis were performed.

由青枯雷尔氏菌（Ralstonia solanacearum）引发的青枯病是一种致死性番茄土传病害。当前采用化学药剂与轮作的病害防控手段效果有限，因该病原菌可极好地适应土壤与根际微环境。故而，品种抗性是防控青枯病最为有效的途径，但抗性应答的分子机制仍未阐明。本研究借助基因芯片（microarrays），分析了抗病品种LS-89与感病品种Ponderosa受青枯雷尔氏菌侵染后诱导产生的基因表达变化特征。实验选取五至六叶期的LS-89与Ponderosa幼苗，在其子叶上方的茎部进行接种：使用剃须刀将茎秆切至原直径的1/3，于伤口处加入5 µl 菌悬液（浓度为1×10^6 CFU/ml的青枯雷尔氏菌菌株8107S），或无菌蒸馏水以开展模拟接种（mock inoculation），随后夹持伤口部位避免茎秆弯折。接种后的植株被置于光照强度30000 lux、每日光照12小时、温度30℃的生长箱中培养。接种后1天，在接种位点下方5 mm处切取5 mm长的茎段进行取样。每次杂交实验使用15株植株的总RNA，本研究共完成3次生物学重复的基因芯片分析。