Comparative Proteomic Analysis of Mature Pollen in Triploid and Diploid Populus deltoides.

Ploidy affects plant growth vigor and cell size, but the relative effects of pollen fertility and allergenicity between triploid and diploid have not been systematically examined. Here we performed comparative analyses of fertility, proteome, and abundances of putative allergenic proteins of pollen in triploid poplar 'ZhongHuai1' ('ZH1', triploid) and 'ZhongHuai2' ('ZH2', diploid) generated from the same parents. The mature pollen was sterile in triploid poplar 'ZH1'. By applying two-dimensional gel electrophoresis (2-DE), a total of 72 differentially expressed protein spots (DEPs) were detected in triploid poplar pollen. Among them, 24 upregulated and 43 downregulated proteins were identified in triploid poplar pollen using matrix-assisted laser desorption/ionisation coupled with time of-flight tandem mass spectrometer analysis (MALDI-TOF/TOF MS/MS). The main functions of these DEPs were related with "S-adenosylmethionine metabolism", "actin cytoskeleton organization", or "translational elongation". The infertility of triploid poplar pollen might be related to its abnormal cytoskeletal system. In addition, the abundances of previously identified 28 putative allergenic proteins were compared among three poplar varieties ('ZH1', 'ZH2', and '2KEN8'). Most putative allergenic proteins were downregulated in triploid poplar pollen. This work provides an insight into understanding the protein regulation mechanism of pollen infertility and low allergenicity in triploid poplar, and gives a clue to improving poplar polyploidy breeding and decreasing the pollen allergenicity.

The heat shock factor gene family in Salix suchowensis: a genome-wide survey and expression profiling during development and abiotic stresses.

Heat shock transcription factors (Hsfs), which act as important transcriptional regulatory proteins, play crucial roles in plant developmental processes, and stress responses. Recently, the genome of the shrub willow Salix suchowensis was fully sequenced. In this study, a total of 27 non-redundant Hsf genes were identified from the S. suchowensis genome. Phylogenetic analysis revealed that the members of the SsuHsf family can be divided into three groups (class A, B, and C) based on their structural characteristics. Promoter analysis indicated that the SsuHsfs promoters included various cis-acting elements related to hormone and/or stress responses. Furthermore, the expression profiles of 27 SsuHsfs were analyzed in different tissues and under various stresses (heat, drought, salt, and ABA treatment) using RT-PCR. The results demonstrated that the SsuHsfs were involved in abiotic stress responses. Our results contribute to a better understanding of the complexity of the SsuHsf gene family, and will facilitate functional characterization in future studies.

Proteomic analysis and candidate allergenic proteins in Populus deltoides CL. "2KEN8" mature pollen.

Proteomic analysis was used to generate a map of Populus deltoides CL. "2KEN8" mature pollen proteins. By applying 2-D electrophoresis, we resolved 403 protein spots from mature pollen. Using the matrix-assisted laser desorption/ionization time time-of-flight/time-of-flight tandem mass spectrometry method, we identified 178 distinct proteins from 218 protein spots expressed in mature pollen. Moreover, out of these, 28 proteins were identified as putative allergens. The expression patterns of these putative allergen genes indicate that several of these genes are highly expressed in pollen. In addition, the members of profilin allergen family were analyzed and their expression patterns were compared with their homologous genes in Arabidopsis and rice. Knowledge of these identified allergens has the potential to improve specific diagnosis and allergen immunotherapy treatment for patients with poplar pollen allergy.