The plant parasitic nematode genus Meloidogyne parasitize almost all flowering crops. Plants respond with a variety of morphological and molecular mechanisms to reduce the effects of pathogens. Proteinase inhibitors (PI), a special group of plant proteins which are small proteins, involve in protective role in the plants attacked by microorganisms. Still, the plant response using PI against nematodes has not been well understood. Therefore, this study was aimed to determine the expression of proteinase inhibitor I (PI-I) gene subsequent the infection of M. incognita, M. javanica, and M. chitwoodi in tomato plants post nematode infections. Molecular methods were used to determine the PI gene expressions at different days post nematode infections in host tissues. Results revealed that the population of M. incognita species reached the highest level of nematode population followed by M. javanica and M. chitwoodi, respectively. All Meloidogyne species induced expression of PI-I gene reached at the utmost level at 3 days post infection (dpi) in host tissues. Relative gene expression level was sharply dropped at 7 dpi, 14 dpi, and 21 dpi in M. incognita induced gene expression in host tissues. Similar results were observed in host tissues after infection of M. javanica and M. chitwoodi. The commonalities of plant response across a diverse Meloidogyne species interaction and the expression of PI gene may be related to plant defense system. Increased level of PI gene expressions in early infection days in host tissues induced by parasitic nematodes may share resemblances to the mechanisms of resistance on biotrophic interactions.

中文翻译：

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根结线虫诱导番茄植株蛋白酶抑制剂（PI）基因的分子研究

植物寄生线虫属根结线虫寄生于几乎所有开花作物。植物以各种形态和分子机制作出反应，以减少病原体的影响。蛋白酶抑制剂（PI）是一类特殊的植物蛋白，属于小蛋白，在受微生物侵袭的植物中起保护作用。尽管如此，植物对线虫使用 PI 的反应还没有得到很好的理解。因此，本研究旨在确定线虫感染后番茄植株中南方根结线虫、爪哇根结线虫和奇伍德线虫感染后蛋白酶抑制剂 I (PI-I) 基因的表达。分子方法用于确定宿主组织中线虫感染后不同天数的 PI 基因表达。结果显示，M. incognita 种达到线虫种群的最高水平，其次是 M. javanica 和 M. chitwoodi。所有根结线虫物种诱导的 PI-1 基因表达在宿主组织中感染后 3 天 (dpi) 达到最高水平。在 7 dpi、14 dpi 和 21 dpi 的南方根结线虫诱导宿主组织中的基因表达时，相对基因表达水平急剧下降。M. javanica 和 M. chitwoodi 感染后，在宿主组织中观察到类似的结果。不同根结线虫物种相互作用中植物反应的共性和 PI 基因的表达可能与植物防御系统有关。寄生线虫诱导的宿主组织中感染早期 PI 基因表达水平的增加可能与生物营养相互作用的抗性机制有相似之处。