کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1589680 1002005 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Occurrence and ultrastructure of Albugo candida on a new host, Arabis alpina in Saudi Arabia
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Occurrence and ultrastructure of Albugo candida on a new host, Arabis alpina in Saudi Arabia
چکیده انگلیسی

A population of Arabis alpina (Brassicaceae) growing in Saudi Arabia was observed to be infected for the first time by the Oomycete, Albugo candida. Both conventional chemical fixation and high pressure freezing followed by freeze substitution (HPF/FS) were used to prepare zoosporangia, intercellular hyphae, haustoria, invading host cells and host–parasite interface of A. candida for study with both scanning and transmission electron microscopy. Both fixations gave good preservation of ultrastructural details and data from the two sample types were highly complementary. Scanning electron microscopic observation revealed that mature zoosporangia of A. candida are spherical or ellipsoidal in shape and characterized by a smooth surface and faint terminal secession scar at each end. Transmission electron microscopic observation indicated that coenocytic intercellular hyphae are located in intercellular spaces of host leaf tissue forming haustoria in host mesophyll cell. Each haustorium is connected to intercellular hyphae by a narrow, slender neck which enclosed by a collar as a response of host cell to infection. The cytoplasm of the haustorium contains different organelles characteristic of the Oomycetes. No obvious responses are observed in host cell organelles following infection which may be due to the presence of a compatibility between the host and the Oomycete. Modifications of the host plasma membrane around the haustorium are detected. Many tubular elements were found to be continuous with the extrahaustorial membrane. This appears to be the first report of the presence of these tubular elements in case of A. candida haustoria. These tubular elements may increase membrane surface area and consequently increase the efficacy of nutrients uptake by haustoria from host cell.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Micron - Volume 39, Issue 8, December 2008, Pages 1138–1144
نویسندگان
,