Project description:Bolting is a key process in the growth and development of lettuce (Lactuca sativa L.). High temperature can induce earlier bolting which decreases in both quality and production of lettuce. However, knowledge underlying lettuce bolting is still lacking. To better understand the molecular basis of bolting, a comparative proteomics analysis was conducted on lettuce stems in the bolting period induced by high temperature (33 °C) compared with a control (20 °C) using iTRAQ-based proteomics, phenotypic measures, and biological verifications. High temperature induced lettuce bolting, while control temperature did not. Of the 6656 proteins identified, 758 proteins significantly altered their expression level induced by high-temperature relative to the control, of which 409 were up-regulated and 349 down-regulated. Proteins with abundance level change were mainly involved in photosynthesis, carbohydrate metabolism, stress response, hormone synthesis, and signal transduction. These differential proteins were mainly enriched in pathways associated with photosynthesis and tryptophan metabolism involving in auxin (IAA) biosynthesis. Among the differentially expressed proteins associated with photosynthesis and tryptophan metabolism were up-regulated. Moreover, in gibberellin (GA) biosynthesis pathway, 10 of main enzymes of P450 were up-regulated. Proteins related to SAUR and GRP, implicated in IAA and GA signal transduction were up-regulated, and the phosphorylation and ubiquitination related proteins regulating IAA and GA signal transduction were also induced. These findings indicate that a high temperature enhances the function of photosynthesis, IAA and GA synthesis and signal transduction to promote the process of bolting, which is in line with the physiology and transcription levels of IAA and GA metabolism. Our data provide a first comprehensive dataset for gaining novel understanding of the molecular basis underlying lettuce bolting induced by high temperature. It is potentially important for further functional analysis and genetic manipulation for molecular breeding to breed new cultivar of lettuce to restrain early bolting, which is vital for improving vegetable quality.
Project description:This study aims to compare the proteome of lactuca sativa cv. Salinas and Lactuca serriola cv. US96UC23 by tandem mass tag quantitative proteomics.