Resumo

ARELLANO, Yazmín; GARCIA, Elpidio  e  VAZQUEZ-RAMOS, Jorge M.. Auxin-Stimulation of DNA synthesis and cell cycle proteins during maize germination. Agrociencia [online]. 2008, vol.42, n.6, pp.637-644. ISSN 2521-9766.

The establishment and progress of the cell cycle are important events for the germination of seeds. In maize the auxins and the exogeniously added cytokinins stimulate the synthesis of DNA during the early hours of germination, and this effect depends, to a greater or lesser extent, on the presence of sucrose in the imbibition buffer. However, in the absence of exogeniously added hormones, the presence or absence of sucrose does not affect the synthesis of DNA at early or late times of germination. Therefore, the effect of the phytoregulators would be more related to the stimulation of a mitogenic action, than to the germinative process per se. When measuring the presence of specific proteins of the phases G1 and S of the cell cycle, in the presence of auxins, it was evident that markers of G1 such as the cyclins D2;1 and D4;1, or markers of the S phase such as cyclin A1 or PCNA, did not change their levels during germination. Besides, the levels of a marker of G1, the cyclin D5;2 and a marker of the S phase, the DNA polymerase a, increased visibly in response to the addition of auxins. This response and in particular that of DNA polymerase a, could explain the increase in the synthesis of DNA caused by the addition of auxins in embryonic axes during germination.

Palavras-chave : Zea mays; auxins; cell cycle; germination.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )