tailieunhanh - báo cáo khoa học: " Identification of a GCC transcription factor responding to fruit colour change events in citrus through the transcriptomic analyses of two mutants"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Identification of a GCC transcription factor responding to fruit colour change events in citrus through the transcriptomic analyses of two mutants | Ríos et al. BMC Plant Biology 2010 10 276 http 1471-2229 10 276 BMC Plant Biology RESEARCH ARTICLE Open Access Identification of a GCC transcription factor responding to fruit colour change events in citrus through the transcriptomic analyses of two mutants 1 1 2 1 I 7 2 1 Gabino Rios Miguel A Naranjo María-Jesús Rodrigo Enriqueta Alós Lorenzo Zacarias Manuel Cercós Manuel Talón 1 Abstract Background External ripening in Citrus fruits is morphologically characterized by a colour shift from green to orange due to the degradation of chlorophylls and the accumulation of carotenoid pigments. Although numerous genes coding for enzymes involved in such biochemical pathways have been identified the molecular control of this process has been scarcely studied. In this work we used the Citrus Clementina mutants 39B3 and 39E7 showing delayed colour break to isolate genes potentially related to the regulation of peel ripening and its physiological or biochemical effects. Results Pigment analyses revealed different profiles of carotenoid and chlorophyll modification in 39B3 and 39E7 mutants. Flavedo from 39B3 fruits showed an overall delay in carotenoid accumulation and chlorophyll degradation while the flavedo of 39E7 was devoid of the apocarotenoid p-citraurin among other carotenoid alterations. A Citrus microarray containing about 20 000 cDNA fragments was used to identify genes that were differentially expressed during colour change in the flavedo of 39B3 and 39E7 mutants respect to the parental variety. The results highlighted 73 and 90 genes that were respectively up- and down-regulated in both mutants. CcGCCl gene coding for a GCC type transcriptional factor was found to be down-regulated. CcGCCl expression was strongly induced at the onset of colour change in the flavedo of parental clementine fruit. Moreover treatment of fruits with gibberellins a retardant of external ripening delayed both colour break and CcGCCl overexpression. Conclusions In .