Increase in BrAO1 gene expression and aldehyde oxidase activity during clubroot development in Chinese cabbage (Brassica rapa L.)
Increase in BrAO1 gene expression and aldehyde oxidase activity during clubroot development in Chinese cabbage (Brassica rapa L.)
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DOI：
10.1111/j.1364-3703.2006.00333.x
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发表时间：
2006-07-01
影响因子：
4.9
通讯作者：
Tabei, Yutaka
中科院分区：
文献类型：
--
作者：
Ando, Sugihiro;Tsushima, Seiya;Tabei, Yutaka
在根肿病中，由于生长素和细胞分裂素水平的增加，通过感染专性生物营养型芸苔根肿菌（Plasmodiophora brassicae）诱导瘿形成。由于醛氧化酶（AO）可能参与植物生长素的生物合成，我们从大白菜（Brassica rapa ssp.）北京变种Muso），并检测了它们在根状茎发育过程中的表达。BrAO 1的表达增强接种根接种后15天（dpi）时，可见的根肿病仍然无法检测到。此后，BrAO 1的表达增加根肿病的发展与未接种的根相比，虽然BrAO 2的表达被抑制。原位杂交显示，BrAO 1强烈表达的组织中，未成熟的疟原虫入侵在35 dpi，这表明，BrAO 1的表达增强的病原体，以建立其发病机制。此外，我们检测AO活性，证明了至少有六个条带（BrAO-a至BrAO-f）的发生在大白菜根中使用苯甲醛和吲哚-3-醛作为底物的活性染色方法。与BrAO 1的表达相一致的是，与健康根相比，在根状茎发育期间接种P. brassicae增加了BrAO-a和BrAO-d的信号，导致总AO活性增加。与此相反，带BrAO-b接种后下降，在平行的表达BrAO 2。其他的活性条带没有明显受到感染的影响。在此基础上，我们讨论了AO在根肿病生长过程中的作用。
In clubroot disease, gall formation is induced by infection with the obligate biotroph Plasmodiophora brassicae due to increased levels of auxins and cytokinins. Because aldehyde oxidase (AO) may be involved in auxin biosynthesis in plants, we isolated two AO genes (BrAO1 and BrAO2) from Chinese cabbage (Brassica rapa ssp. pekinensis cv. Muso), which are the most similar to AAO1 among Arabidopsis AO genes, and examined their expressions during clubroot development. The expression of BrAO1 was enhanced in inoculated roots from 15 days post-inoculation (dpi) when visible clubroots were still undetectable. Thereafter, BrAO1 expression increased with clubroot development compared with uninoculated roots, although BrAO2 expression was repressed. In situ hybridization revealed that BrAO1 was strongly expressed in tissues that were invaded by immature plasmodia at 35 dpi, suggesting that BrAO1 expression was enhanced by the pathogen in order to establish its pathogenesis. In addition, we detected AO activity, as evidenced by the occurrence of at least six bands (BrAO-a to BrAO-f) in the roots of Chinese cabbage using an active staining method with benzaldehyde and indlole-3-aldehyde as the substrate. Coincidental with BrAO1 expression, the signals of BrAO-a and BrAO-d increased with inoculation by P. brassicae during clubroot development compared with healthy roots, resulting in an increase in total AO activity. By contrast, the band BrAO-b decreased post-inoculation, in parallel with the expression of BrAO2. The other bands of activity were not clearly influenced by the infection. Based on these results, we discuss the involvement of AO in auxin-overproduction during clubroot development in Chinese cabbage.