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

RUGGERI, GERMÁN; TRIASSI, AGUSTINA; ALVAREZ, CLARISA ESTER; GOLA, ADRIÁN; WIGGENHAUSER, J; BUDDE, CLAUDIO OLAF; LARA, MARÍA VALERIA; DRINCOVICH, MARÍA FABIANA; MÜLLER, GABRIELA LETICIA

BIOLOGIA PLANTARUM

SPRINGER

Lugar: Berlin; Año: 2018 vol. 62 p. 501 - 510

0006-3134

Glycine-rich RNA-binding proteins (GR-RBPs) are output signals of the circadian clock involved in RNA stabilization and transcript processing. 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 metabolismRNA stabilization in fruits, Solanum lycopersicum cv Micro-Tom was transformed with preLeGRP1a fussed 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.