Sugarcane (Saccharum spp.) is an important sugar crop. Biotic and abiotic stresses such as diseases, cold, and drought are major factors limiting sugarcane production. β-1,3-glucanase (EC 3.2.1.39), a member of the pathogenesis-related protein family, plays an essential role not only in the plant defenses against pathogens but also in plant growth, development, and abiotic stress responses. To systematically investigate the sugarcane β-1,3-glucanase gene family, 132 glycoside hydrolase (GH) 17 family members were identified in the genomes of the sugarcane wild species Saccharum spontaneum 'Np-X', the tropical species S. officinarum 'LA-Purple', and the Saccharum spp. hybrid cultivar 'R570'. The results of the phylogenetic analysis categorized them into four subfamilies, of which subfamily Ⅳ had the largest proportion of members (102). The members of the sugarcane GH17 gene family contained five conserved motifs and 0-16 introns. The majority of the GH17 genes exhibited a genome-wide replication pattern, with 89.50% originating from S. spontaneum 'Np-X' and S. officinarum 'LA-Purple', while 58.10% of them in the Saccharum spp. hybrid cultivar 'R570' belonged to the discrete replication type. Four major classes of cis-acting elements were identified in the promoters, including the elements related to plant growth, development, and tissue-specific expression (14.21%), light-responsive elements (38.24%), biotic or abiotic stress-responsive elements (9.18%), and hormone-responsive elements (38.37%), which suggested that this gene family was involved in plant growth, development, hormone responses, and stress responses. Transcriptome and quantitative real-time PCR (RT-qPCR) analyses showed that the sugarcane GH17 genes exhibited tissue-specific expression and were differentially expressed under low temperature, drought, and hormone treatments, as well as during the interactions between different sugarcane genotypes and Sporisorium scitamineum, suggesting their potential roles in plant defenses. In addition, some SsGlu genes (SsGlu5, SsGlu20, SsGlu21, SsGlu25, SsGlu28, and SsGlu39) were expected to serve as candidate stress-related genes. This study lays a foundation for further revealing the molecular mechanisms of the stress resistance of sugarcane via β-1,3-glucanase genes.
Saccharum/physiology* ; Stress, Physiological/genetics* ; Glucan 1,3-beta-Glucosidase/metabolism* ; Multigene Family ; Phylogeny ; Gene Expression Regulation, Plant ; Plant Proteins/genetics*

Gelsemium elegans, a vine plant of Loganiaceae, has both medicinal and forage values. However, it is susceptible to low temperatures during growth. Exploring low temperature response genes is of great significance for cold resistance breeding of G. elegans. Ethylene response factors (ERFs) are the transcription factors of the AP2/ERF superfamily and play a crucial role in plant stress response. In this study, based on the unigene GeERF involved in the response to low temperature stress in the transcriptome of G. elegans, a full-length cDNA sequence of the transcription factor GeERF4B-1 was cloned from the leaves of G. elegans by reverse transcription-polymerase chain reaction (RT-PCR). Bioinformatics analysis showed that GeERF4B-1 had an open reading frame of 759 bp, encoding a protein composed of 252 amino acid residues and with a relative molecular weight of 27 kDa. The deduced protein was predicted to be an unstable, alkaline, and hydrophilic protein. The phylogenetic tree showed that GeERF4B-1 was in the same clade as the B-4 subfamily of the ERF family. The results of the subcellular localization experiment revealed that GeERF4B-1 was located in the nucleus. Real time quantitative PCR (RT-qPCR) analysis indicated that GeERF4B-1 was expressed in the root, stem, and leaf of G. elegans, with the highest expression level in the root. Compared with the control, the treatments with a low temperature (4 ℃), methyl jasmonate (MeJA), and abscisic acid (ABA) up-regulated the expression level of GeERF4B-1, which reached the peak at 24-48 h. This result revealed that GeERF4B-1 actively responded to low temperature, MeJA, and ABA stresses. However, both sodium chloride (NaCl) and drought treatments down-regulated the expression of GeERF4B-1. In addition, a prokaryotic expression vector of GeERF4B-1 was constructed, and a fusion protein of approximately 52 kDa was yielded after induced expression. The results of the plate stress assay showed that compared with the control, the prokaryotic strain expressing GeERF4B-1 demonstrated enhanced tolerance to low temperatures and sensitivity to salt and mannitol stresses. This study provides theoretical references and potential genetic resources for breeding G. elegans varieties with stress resistance.
Transcription Factors/metabolism* ; Plant Proteins/metabolism* ; Gelsemium/metabolism* ; Acetates/pharmacology* ; Gene Expression Regulation, Plant ; Phylogeny ; Cold Temperature ; Amino Acid Sequence ; Cyclopentanes/metabolism* ; Oxylipins/metabolism* ; Stress, Physiological/genetics* ; Abscisic Acid/metabolism* ; Cloning, Molecular

OBJECTIVETo establish an efficient and high resolution 2-DE (two-dimensional electrophoresis) protocol for root tuber proteome analysis of Rehmannia glutinosa.

METHODProteins from root tuber of R. glutinosa were extracted by using five different methods and their productivity and profiles were assessed by means of SDS-PAGE and two-dimensional electrophoresis.

RESULTThe trichloroacetic acid (TCA)-phenol extraction method was found most effective for the extraction with the highest protein yield, the most spots in protein patterns, and the highest resolution of proteins, and the clearest background could be achieved simultaneously. A 1:5 solution of ampholine pH 3-10 and pH 5-8 for a nonlinear gel and the 170 microg of protein loading dosage obtained maps with more protein spots and higher resolution of separation patterns.

CONCLUSIONThis study based on the optimized root tuber proteome preparation and the 2-DE protocol gets a high resolution and reproducibility 2-DE image, which will be expected to have excellent applications in proteomics studies of R. glutinosa tuber root.

Electrophoresis, Gel, Two-Dimensional ; methods ; Plant Proteins ; analysis ; chemistry ; Plant Roots ; chemistry ; Proteome ; chemistry ; isolation & purification ; Rehmannia ; chemistry