Instituto de Biotecnología de las Plantas, Universidad Central Marta Abreu de Las Villas, Carretera a Camajuaní km 5.5, 54 830 Santa Clara, Cuba.
Plant Cell Rep. 2012 May;31(5):955-69. doi: 10.1007/s00299-011-1216-6. Epub 2012 Jan 3.
Brown rust caused by the fungus Puccinia melanocephala is a major disease of sugarcane (Saccharum spp.). A sugarcane mutant, obtained by chemical mutagenesis of the susceptible variety B4362, showed a post-haustorial hypersensitive response (HR)-mediated resistance to the pathogen and was used to identify genes differentially expressed in response to P. melanocephala via suppression subtractive hybridization (SSH). Tester cDNA was derived from the brown rust-resistant mutant after inoculation with P. melanocephala, while driver cDNAs were obtained from the non-inoculated resistant mutant and the inoculated susceptible donor variety B4362. Database comparisons of the sequences of the SSH recombinant clones revealed that, of a subset of 89 non-redundant sequences, 88% had similarity to known functional genes, while 12% were of unknown function. Thirteen genes were selected for transcript profiling in the resistant mutant and the susceptible donor variety. Genes involved in glycolysis and C4 carbon fixation were up-regulated in both interactions probably due to disturbance of sugarcane carbon metabolism by the pathogen. Genes related with the nascent polypeptide associated complex, post-translational proteome modulation and autophagy were transcribed at higher levels in the compatible interaction. Up-regulation of a putative L-isoaspartyl O-methyltransferase S-adenosylmethionine gene in the compatible interaction may point to fungal manipulation of the cytoplasmatic methionine cycle. Genes coding for a putative no apical meristem protein, S-adenosylmethionine decarboxylase, non-specific lipid transfer protein, and GDP-L-galactose phosphorylase involved in ascorbic acid biosynthesis were up-regulated in the incompatible interaction at the onset of haustorium formation, and may contribute to the HR-mediated defense response in the rust-resistant mutant.
由真菌 Puccinia melanocephala 引起的褐锈病是甘蔗（Saccharum spp.）的主要病害。通过对易感品种 B4362 进行化学诱变，获得了一种甘蔗突变体，该突变体对病原体表现出了后haustorial 超敏反应（HR）介导的抗性，并被用于通过抑制差减杂交（SSH）鉴定对 P. melanocephala 反应不同的基因。测试 cDNA 是从接种 P. melanocephala 后的褐锈抗性突变体中获得的，而驱动 cDNA 则是从未接种的抗性突变体和接种的易感供体品种 B4362 中获得的。对 SSH 重组克隆序列的数据库比较表明，在一组 89 个非冗余序列中，88%与已知功能基因具有相似性，而 12%则具有未知功能。选择了 13 个基因用于在抗性突变体和易感供体品种中进行转录谱分析。在这两种相互作用中，与糖酵解和 C4 碳固定相关的基因都上调表达，这可能是由于病原体对甘蔗碳代谢的干扰。与新生多肽相关的复合物、翻译后蛋白质组修饰和自噬相关的基因在相容相互作用中转录水平更高。在相容相互作用中，一个假定的 L-异天冬氨酸 O-甲基转移酶 S-腺苷甲硫氨酸基因的上调可能表明真菌对细胞质甲硫氨酸循环的操纵。在起始吸器形成时，与非特异性脂转移蛋白和 GDP-L-半乳糖磷酸化酶相关的假定无顶端分生组织蛋白、S-腺苷甲硫氨酸脱羧酶、参与抗坏血酸生物合成的基因在不亲和相互作用中上调，可能有助于褐锈抗性突变体中 HR 介导的防御反应。
