OTAIZA GONZÁLEZ SANTIAGO NICOLÁS
Congresos y reuniones científicas
Título:
A Sec14-like protein regulates tocopherol content in transgenic tomato plants.
Reunión:
Congreso; Plant Metabolic Engineering; 2011
Institución organizadora:
Gordon Reserch Conference
Resumen:
SEC14-like proteins have been identified in all kingdoms and showed to be involved in
membrane trafficking, regulation of phospholipid metabolism and phosphoinositide signaling
pathways. Based on metabolic QTL mapping data from a S. pennellii introgression lines
population in the genetic background of S. lycopersicum (cv. M82), our group has identified a
SEC14-like protein co-localizing with a α-tocopherol QTL on chromosome 9. We present here
results on the functional characterization of this protein in tomato, including: sequence analyses,
expression profiles and sub-cellular localization experiments for both alleles. Moreover, iRNA
tomato plants showed impairment in the photosynthetic performance and revealed alterations in
sugars and tocopherol contents. Source leaves of independent transgenic lines presented ~0.3- to
0.5 and ~0.3- to 0.6-fold lower levels of α-tocopherol and γ-tocopherol, respectively, than those
in control plants. In addition, the levels of total tocopherol in iRNA-SEC14 fruits decreased up
to 0.2-fold and 0.5-fold, as compared to the control fruits. Moreover, expression analyses of the
genes encoding for VTE core pathway enzymes (VTE1, VTE2, VTE3, VTE4, VTE5 and
HPPD) showed no altered profiles in the transgenic lines. The exception is the case of vte5 gene
which showed differential expression in both, leaves and red fruits, suggesting that a
transcriptional regulatory point operates on this gene and allowed us to propose that the tomato
SEC14-like protein participates in the control of tocopherol biosynthesis in tomato plants.