Proteome analysis of Pueraria mirifica tubers collected in different seasons

The Eucalyptus grandis chloroplast proteome: Seasonal variations in leaf development

Chloroplast metabolism is very sensitive to environmental fluctuations and is intimately related to plant leaf development. Characterization of the chloroplast proteome dynamics can contribute to a better understanding on plant adaptation to different climate scenarios and leaf development processes. Herein, we carried out a discovery-driven analysis of the Eucalyptus grandis chloroplast proteome during leaf maturation and throughout different seasons of the year. The chloroplast proteome from young leaves differed the most from all assessed samples. Most upregulated proteins identified in mature and young leaves were those related to catabolic-redox signaling and biogenesis processes, respectively. Seasonal dynamics revealed unique proteome features in the fall and spring periods. The most abundant chloroplast protein in humid (wet) seasons (spring and summer) was a small subunit of RuBisCO, while in the dry periods (fall and winter) the proteins that showed the most pronounced accumulation were associated with photo-oxidative damage, Calvin cycle, shikimate pathway, and detoxification. Our investigation of the chloroplast proteome dynamics during leaf development revealed significant alterations in relation to the maturation event. Our findings also suggest that transition seasons induced the most pronounced chloroplast proteome changes over the year. This study contributes to a more comprehensive understanding on the subcellular mechanisms that lead to plant leaf adaptation and ultimately gives more insights into Eucalyptus grandis phenology.

Hormonal and transcriptional analyses provides new insights into the molecular mechanisms underlying root thickening and isoflavonoid biosynthesis in Callerya speciosa (Champ. ex Benth.) Schot

Callerya speciosa (Champ. ex Benth.) Schot is a traditional Chinese medicine characterized by tuberous roots as the main organ of isoflavonoid accumulation. Root thickening and isoflavonoid accumulation are two major factors for yield and quality of C. speciosa. However, the underlying mechanisms of root thickening and isoflavonoid biosynthesis have not yet been elucidated. Here, integrated morphological, hormonal and transcriptomic analyses of C. speciosa tuberous roots at four different ages (6, 12, 18, 30 months after germination) were performed. The growth cycle of C. speciosa could be divided into three stages: initiation, rapid-thickening and stable-thickening stage, which cued by the activity of vascular cambia. Endogenous changes in phytohormones were associated with developmental changes during root thickening. Jasmonic acid might be linked to the initial development of tuberous roots. Abscisic acid seemed to be essential for tuber maturation, whereas IAA, cis-zeatin and gibberellin 3 were considered essential for rapid thickening of tuberous roots. A total of 4337 differentially expressed genes (DEGs) were identified during root thickening, including 15 DEGs participated in isoflavonoid biosynthesis, and 153 DEGs involved in starch/sucrose metabolism, hormonal signaling, transcriptional regulation and cell wall metabolism. A hypothetical model of genetic regulation associated with root thickening and isoflavonoid biosynthesis in C. speciosa is proposed, which will help in understanding the underlying mechanisms of tuberous root formation and isoflavonoid biosynthesis.

Quantitative Proteome Reveals Variation in the Condition Factor of Sea Urchin Strongylocentrotus nudus during the Fishing Season Using an iTRAQ-based Approach

To investigate the variation in the condition factor of the sea urchin Strongylocentrotus nudus (S. nudus), gonads were collected in May (MAY), June (JUN), and July (JUL), at the beginning (AUG-b) and end of August (AUG-e). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) detection of the gonads revealed an obvious enhancement of the band at about 37 kDa from July, which was identified as transforming growth factor-beta-induced protein ig-h3 (TGFBI) by nanoLC-ESI-MS/MS. Gonadal proteins were identified by isobaric tagging for relative and absolute quantitation (iTRAQ), and regulation of the identified proteins in pairs of the collected groups was observed. A total of 174 differentially expressed proteins (DEPs) were identified. Seven of the DEPs showed significant correlations with both the gonad index (GI) and protein content. These correlations included 6-phosphogluconate dehydrogenase, decarboxylating isoform X2 (6PGD), CAD protein, myoferlin isoform X8, ribosomal protein L36 (RL36), isocitrate dehydrogenase [NADP], mitochondrial isoform X2 (IDH), multifunctional protein ADE2 isoform X3, sperm-activating peptides (SAPs) and aldehyde dehydrogenase, and mitochondrial (ALDH). However, TGFBI had no correlation with gonad index (GI) or protein content. 6PGD, IDH, multifunctional protein ADE2 isoform X3, and ALDH were shown to interact with each other and might play key roles in changing the condition factor of S. nudus gonads.

Comparative protein profiles of Butea superba tubers under seasonal changes

Seasonal changes are major factors affecting environmental conditions which induce multiple stresses in plants, leading to changes in protein relative abundance in the complex cellular plant metabolic pathways. Proteomics was applied to study variations in proteome composition of Butea. superba tubers during winter, summer and rainy season throughout the year using two-dimensional polyacrylamide gel electrophoresis coupled with a nanoflow liquid chromatography coupled to electrospray ionization quadrupole-time-of-flight tandem mass spectrometry. A total of 191 protein spots were identified and also classified into 12 functional groups. The majority of these were mainly involved in carbohydrate and energy metabolism (30.37 %) and defense and stress (18.32 %). The results exhibited the highest numbers of identified proteins in winter-harvested samples. Forty-five differential proteins were found in different seasons, involving important metabolic pathways. Further analysis indicated that changes in the protein levels were due mainly to temperature stress during summer and to water stress during winter, which affected cellular structure, photosynthesis, signal transduction and homeostasis, amino-acid biosynthesis, protein destination and storage, protein biosynthesis and stimulated defense and stress mechanisms involving glycolytic enzymes and relative oxygen species catabolizing enzymes. The proteins with differential relative abundances might induce an altered physiological status within plant tubers for survival. The work provided new insights into the better understanding of the molecular basis of plant proteomes and stress tolerance mechanisms, especially during seasonal changes. The finding suggested proteins that might potentially be used as protein markers in differing seasons in other plants and aid in selecting B. superba tubers with the most suitable medicinal properties in the future.