biologia plantarum

Biologia plantarum 57:291-297, 2013 | DOI: 10.1007/s10535-012-0276-y

The role of spherosome-like vesicles in formation of cytomictic channels between tobacco microsporocytes

S. Mursalimov^1,*, Y. Sidorchuk¹, E. Deineko¹

¹ Laboratory of Plant Bioengineering, Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia

The formation of cytomictic channels (CCs) during the tobacco microsporogenesis has been analyzed by microscopy and cytochemical methods. Starting from the pachytene stage, CCs were formed between microsporocytes with involvement of specific organelles, the so-called spherosome-like vesicles. The presence of the enzyme callase, able to degrade callose and form CCs in the cell wall of microsporocytes, has been demonstrated for the first time in the spherosome-like vesicles. An active form of callase was detectable in the spherosome-like vesicles and cell wall but not in the endoplasmic reticulum and Golgi apparatus. The release of callase from spherosome-like vesicles into the cell wall was described. Two ways in formation of the CCs in the tobacco microsporogenesis, the primary formation in the cell wall composed of pectins and cellulose (leptotene-zygotene) and secondary formation in the cell wall of callose (after the pachytene stage), were compared.

Keywords: callase; cytomixis; microsporogenesis; Nicotiana tabacum; plasmodesmata

Subjects: spherosome-like vesicles; cytomictic channels; microsporogenesis; tobacco; pollen; callase; plasmodesmata; ultrastructure

Received: May 13, 2012; Accepted: July 23, 2012; Published: June 1, 2013  Show citation