Vega Jorge, Scagliusi Sandra M M, Ulian Eugênio C
Department of Plant Physiology, Institute of Biology, Universidade Estadual de Campinas (UNICAMP), C.P. 6109, 13083-970 Campinas, SP, Brazil.
Section of Virology, Instituto Agronômico, C.P.28, 13001-001 Campinas, SP, Brazil.
Plant Dis. 1997 Jan;81(1):21-26. doi: 10.1094/PDIS.1997.81.1.21.
Evidence of the viral etiology of sugarcane yellow leaf disease (SCYLD), occurring in southeast Brazil, was obtained by light and electron microscopy combined with serology. Light microscopy using epifluorescence illumination showed an abnormal yellow-green fluorescing material in the phloem of SCYLD-affected plants that was rarely observed in control plants. Immunolocalization in tissue-printed (or -blotted) nitrocellulose membranes, using barley yellow dwarf virus (BYDV) serotype PAV antiserum, showed a weak but clearly positive reaction in the phloem. Isometric viruslike particles of 24 to 26 nm in diameter were found by electron microscopy both in situ and in partially purified preparations. Examination of thin sections showed that phloem companion cells contained viruslike particles and presented cytological changes apparently related to the development of virus infection. Partially purified preparations produced UV absorption spectra typical of a nucleoprotein, with high absorbance at 260 nm, as expected for isometric virus particles. Virus particles were observed in extracts and partially purified preparations using immunosorbent electron microscopy with BYDV-PAV antiserum. Plate-trapped antigen enzyme-linked immunosorbent assays with the same antiserum indicate a weak serological relationship between BYDV-PAV and SCYLD-associated virus.
通过光学显微镜和电子显微镜结合血清学方法，获得了巴西东南部甘蔗黄叶病（SCYLD）病毒病因的证据。使用落射荧光照明的光学显微镜显示，受SCYLD影响的植物韧皮部中存在异常的黄绿色荧光物质，而在对照植物中很少观察到。使用大麦黄矮病毒（BYDV）血清型PAV抗血清在组织印迹（或斑点）硝酸纤维素膜上进行免疫定位，结果显示韧皮部有微弱但明显的阳性反应。通过电子显微镜在原位和部分纯化的制剂中均发现了直径为24至26 nm的等轴病毒样颗粒。对薄片的检查表明，韧皮部伴胞含有病毒样颗粒，并呈现出明显与病毒感染发展相关的细胞学变化。部分纯化的制剂产生了核蛋白典型的紫外吸收光谱，在260 nm处有高吸光度，这与等轴病毒颗粒预期的情况一致。使用BYDV-PAV抗血清通过免疫吸附电子显微镜在提取物和部分纯化的制剂中观察到病毒颗粒。使用相同抗血清的板条捕获抗原酶联免疫吸附测定表明，BYDV-PAV与SCYLD相关病毒之间存在微弱的血清学关系。
