EFFECT OF PLANT REGULATORS ON THE EXPRESSION OF BoPAO AND BoLOX1 DURING SENESCENCE OF BROCCOLI

GÓMEZ LOBATO ME; CIVELLO PM; MARTÍNEZ GA

Tucumán

Congreso; XLV Reunión Anual SAIB; 2009

SAIB

Plant senescence involves several events that occur at the finalstages of development, or are initiated in response to a stress. Thecharacteristics symptom is the loss of green color caused bychlorophyll degradation. Broccoli (Brassica oleracea) is avegetable belonging to the group of Coles, included in the family ofCruciferae. Broccoli is harvested when their inflorescences are stillimmature, which causes considerable stress and triggers thesenescence. In this work, it was studied by RT-PCR the effect ofdifferent plant regulators on the expression of two genes normallyassociated to senescence: PHEOPHORBIDE A OXYGENASE(PAO), involved in chlorophyll degradation and LIPOXYGENASE 1(LOX 1), associated to lipid degradation and to the synthesis ofjasmonic acid. Broccolis were treated with cytokine and ethylene, inorder to delay or accelerate senescence, respectively. It wasobserved that, after three days, the expression of PAO decreasessignificantly in both treatments. After 5 days, samples treated withethylene increased the expression of PAO over control whilecytokine treated samples showed a decrement of almost 50% in PAOexpression. In the case of LOX1, it was observed that the expressionsignificantly decreased in both treatments after 3 days. However,treatment with ethylene increased the expression of LOX1 whilecytokine did not affect this expression after 5 days.