Nitrogen metabolism in cultured cotyledon explants of Pinus radiata during de novo organogenesis [glutamate synthase, glutamine synthetase]

absorption de substances nutritives acide glutamique ammonia ammoniac azote cotiledones cotyledons culture techniques enzymic activity etapas de desarrollo de la planta explant explantes explants glutamate ammonia ligase glutamate dehydrogenase glutamic acid glutamina glutamina sintetasa glutamine glutamine synthetase nitrogen nitrogen metabolism nutrient uptake organogenese organogenesis pinus radiata plant developmental stages plant vegetative organs technique de culture variedades varieties