Overexpression of Glycine Rich RNA binding protein in tomato renders fruits with higher protein content after cold storage

RUGGIERI GERMAN; TRIASSI AGUSTINA; CLARISA E. ALVAREZ; GOLA ALDANA; WIGGENHAUSER JULIETA; BUDDE CLAUDIO; LARA, M. VALERIA; DRINCOVICH, MA. FABIANA; MÜLLER GABRIELA

BIOLOGIA PLANTARUM

SPRINGER

Lugar: Berlin; Año: 2018

0006-3134

Glycine-rich RNA-binding proteins (GR-RBPs) are involved in RNA processing and also some of them are output signals of the circadian clock. In tomato, one GR-RBP family (LeGRP1) is composed by three highly homologous genes (LeGRP1a-c); each one rendering three transcriptional products: the un-spliced pre-RNA (preLegrp1a-c), the mature mRNA (mLegrp1a-c) and the alternatively spliced mRNA (asLegrp1a-c). To get insight into their regulation and impact on RNA metabolism in fruits, Solanum lycopersicum cv Micro-Tom was transformed with preLeGRP1a fused to the polygalacturonase promoter, which drives expression to fruits from the mature green stage. Our results demonstrate a complex positive regulation of LeGRPs, in which LeGRP1a overexpression leads to the induction of the other LeGRP1 members. Even though the transcripts and protein levels of the three LeGRPs are affected, the overall LeGRP protein circadian rhythm profile is similar in transgenic and WT fruits. Remarkable, when the fruits are kept at chilling temperature after harvest, total protein content is significantly higher in transgenic than in WT fruits, and the level of some free amino acids is modified. The results obtained suggest a critical role of LeGRP1s, probably by inducing structural rearrangements and/or stabilization of mRNA, to allow efficient processing under cold conditions in fruits.