Spatial-temporal and quantitative analysis of growth and EPSI production by Ralstonia solanacearum in resistant and susceptible tomato cultivars
Spatial-temporal and quantitative analysis of growth and EPSI production by Ralstonia solanacearum in resistant and susceptible tomato cultivars
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DOI：
10.1094/phyto.1999.89.12.1233
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发表时间：
1999-12-01
期刊：
影响因子：
3.2
通讯作者：
Schell, MA
中科院分区：
文献类型：
--
作者：
McGarvey, JA;Denny, TP;Schell, MA
研究了1个番茄敏感品种和2个番茄抗性品种在番茄枯败菌侵染方面的差异，以及随后的繁殖、定植和诱导萎蔫毒力因子外多糖I （EPS I）的产生。细菌进入主根的速度在敏感cv中最快。玛丽安，然后是抗药性的简历。L285（慢5倍）和夏威夷7996（慢15倍）。一旦进入主根，在一定程度上，茄红霉几乎在抗性和易感植物的所有区域定殖。然而，根据中茎细菌的活细胞计数，易感品种的定植发生得比抗性品种快。敏感品种的增殖率和最大细菌细胞密度也大于抗性品种。利用侵染植株和未侵染植株的木质部液进行的生长实验表明，抗菌素活性和木质部液中支持生长的营养物质水平的降低都不是抗性品种细菌繁殖减少的原因。利用酶联免疫吸附法对侵染植株的EPS I进行定量分析，结果表明，敏感品种的细菌群体每株产生的EPS I量高于抗性品种。利用免疫荧光显微镜检测抗EPS I和抗EPS I细胞的结果表明，细菌和EPS I分布在敏感品种的维管束和髓的细胞间隙中，而在抗性品种中，细菌和EPS I仅限于维管束组织。
One susceptible and two resistant cultivars of tomato were tested for differences in infection by Ralstonia solanacearum and for the subsequent multiplication, colonization, and production of the wilt-inducing Virulence factor, exopolysaccharide I (EPS I). Bacterial ingress into the taproot was fastest in the susceptible cv. Marion, followed by the resistant cvs. L285 (fivefold slower) and Hawaii 7996 (15-fold slower). Once inside the taproot, R. solanacearum colonized, to some extent, almost all regions of the resistant and susceptible plants. However, colonization occurred sooner in the susceptible than in the resistant cultivars, as measured by viable cell counts of bacteria in the midstems. Rates of multiplication and maximum bacterial cell densities were also greater in the susceptible than in the resistant cultivars. Growth experiments utilizing xylem fluid from infected and uninfected plants indicated that neither antimicrobial activities nor reduced levels of growth-supporting nutrients in the xylem fluids were responsible for the reduced bacterial multiplication in the resistant cultivars. Quantification of EPS I in the infected plants, using an enzyme-linked immunosorbent assay, revealed that the bacterial populations in the susceptible cultivar produced greater amounts of EPS I per plant than those in the resistant cultivars. Immunofluorescence microscopy using antibodies against either EPS I or R. solanacearum cells revealed that bacteria and EPS I were distributed throughout the vascular bundles and intercellular spaces of the pith in the susceptible cultivar, whereas in the resistant cultivars, bacteria and EPS I were restricted to the vascular tissues.