Resumo

HENRIQUES, Fernando Santos. The green revolution and the molecular biology. Rev. de Ciências Agrárias [online]. 2009, vol.32, n.2, pp.245-254. ISSN 0871-018X.

At the turn of this century, the genes responsible for the height reduction of the wheat and rice varieties that made possible the so-called Green Revolution of the 1960s were identified. More recently, it has been shown that this change in plant architecture results from a lack of gibberellin effects, the hormones that cause the internode elongation of stems, but whereas in wheat the reduction in size was accounted for by a gain of function mutation that interfere with the signalling pathway of the gibberellins, in the rice resulted from a loss of function mutation that prevents the synthesis of those hormones. Although gibberellins are the major hormones responsible for stem elongation, it is discussed a maize mutant in which the height reduction is caused by a decrease in auxin availability. These and other discoveries in molecular biology provide the new revolution required in agriculture with new tools in order to fulfil the global demand for increased food production, under the pressure of a continuous expansion of crops for energy production.

Palavras-chave : Auxins; gibberellins; Green Revolution; semi-dwarfing genes; transgenics.

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