Jun-Wei Zhang

Bio: Jun-Wei Zhang is an academic researcher from Huazhong Agricultural University. The author has contributed to research in topics: Amplified fragment length polymorphism & Gene. The author has an hindex of 5, co-authored 6 publications receiving 57 citations.

Over-Expression of PmHSP17.9 in Transgenic Arabidopsis thaliana Confers Thermotolerance

Abstract: Small heat shock proteins (sHSPs) have been shown to be involved in stress tolerance. However, their functions in Prunus mume under heat treatment are poorly characterized. To improve our understanding of sHSPs, we cloned a sHSP gene, PmHSP17.9, from P. mume. Sequence alignment and phylogenetic analysis indicated that PmHSP17.9 was a member of plant cytosolic class III sHSPs. Besides heat stress, PmHSP17.9 was also upregulated by salt, dehydration, oxidative stresses and ABA treatment. Leaves of transgenic Arabidopsis thaliana that ectopically express PmHSP17.9 accumulated less O2 − and H2O2 compared with wild type (WT) after 42 °C treatment for 6 h. Over-expression of PmHSP17.9 in transgenic Arabidopsis enhanced seedling thermotolerance by decreased relative electrolyte leakage and MDA content under heat stress treatment when compared to WT plants. In addition, the induced expression of HSP101, HSFA2, and delta 1-pyrroline-5-carboxylate synthase (P5CS) under heat stress was more pronounced in transgenic plants than in WT plants. These results support the positive role of PmHSP17.9 in response to heat stress treatment.

Establishment of AFLP technique and assessment of primer combinations for mei flower

Abstract: Mei flower is one of the most famous ornamental flowers in eastern Asia for its blossoming in early spring. Amplified fragment length polymorphism (AFLP) is one of the most frequently used techniques for analysis of genetic variation and is used herein for the first time inPrunus mume. This research provides a detailed and modified AFLP protocol for Mei genomic DNA digested withEcoRI/PstI restriction endonuclease combinations. The 10 best primer pairs of high polymorphism were screened from 256 primer combinations that could reliably and repetitively distinguish 14 Mei samples and would be suitable for genetic analysis of more cultivars. Ten primer pairs produced up to a total of 524 AFLP bands and up to 233 polymorphic bands. The ratio of polymorphic bands scoped from 35.71% to 59.67%, and the average ratio was 44.46% in the 10 primers. AFLP is an effective, inexpensive, and timesaving technique for the genetic differentiation of the Mei cultivars, as evidenced in this study.

Genome-wide identification and classification of the Hsf and sHsp gene families in Prunus mume, and transcriptional analysis under heat stress.

Abstract: The transcriptional activation of heat shock proteins (Hsps) by heat shock transcription factors (Hsfs) is presumed to have a pivotal role in plant heat stress (HS) response. Prunus mume is an ornamental woody plant with distinctive features, including rich varieties and colors. In this study, 18 Hsfs and 24 small Hsps (sHsps) were identified in P. mume. Their chromosomal locations, protein domains, conserved motifs, phylogenetic relationships, and exon-intron structures were analyzed and compared with Arabidopsis thaliana Hsfs or sHsps. A total of 18 PmHsf members were classified into three major classes, A, B, and C. A total of 24 PmsHsps were grouped into eight subfamilies (CI to CIII, P, endoplasmic reticulum, M, and CI- or P-related). Quantitative reverse transcription PCR analysis revealed that members of the A2, A7, and A9 groups became the prominent Hsfs after heat shock, suggesting their involvement in a key regulatory role of heat tolerance. Most of the PmsHsp genes were up-regulated upon exposure to HS. Overall, our data contribute to an improved understanding of the complexity of the P. mume Hsf and sHsp gene families, and provide a basis for directing future systematic studies investigating the roles of the Hsf and sHsp gene families.

Genetic relatedness and genetic diversity of ornamental mei (Prunus mume Sieb. et Zucc.) as analysed by AFLP markers

Abstract: The genetic diversity and genetic relatedness of mei (Prunus mume; 2n = 16) were studied using amplified fragment length polymorphism (AFLP) markers. Eight EcoRI–PstI AFLP primer combinations were applied to 121 distinct genotypes of mei cultivars and related species. A total of 508 AFLP product bands were produced, of which 382 were polymorphic. The unweighted pair group method with arithmetic averages analysis was carried out based on these AFLP markers. From this analysis, “Qugeng Mei,” “Yan Mei,” “Chaodou Mei,” and mei cultivars were seen to share the same P. mume genetic stem. The AFLP data were able to clearly discriminate P. mume from other species in the genus Prunus, with P. armeniaca aligning as its closest related species. Two major groups and nine subgroups of mei flower were identified, and there was a strong coincidence of these AFLP-based groupings with the respective morphological characters of the accessions. The genetic diversity of mei accessions was greatest in the Yunnan Province and decreased toward Eastern China and Japan, so supporting the hypothesis that the southwest of China represents the genetic diversity center of the species.

Structural and expression analyses of three PmCBFs from Prunus mume

Abstract: C-repeat binding factor (CBF), also called the dehydration-responsive element binding factor 1 (DREB1), can be induced by low-temperature (LT), and plays an important role in abiotic stress tolerance in higher plants. In present study, two new homologous genes of CBF from Prunus mume (PmCBFb and PmCBFc) have been identified and characterized. The complete coding sequences of PmCBFb and PmCBFc were 714 and 723 bp, respectively. They encoded putative proteins of 237 and 240 amino acids. Neither of them had introns. Genome PCR sequencing showed that PmCBFb was arranged in tandem with PmCBFa (another CBF/DREB1 homolog in P. mume) within a region of nearly 4 kb. Promoter prediction analyses indicated that multiple types of cis-elements related to abiotic stress and irradiance existed in the putative promoter region of PmCBFb. LT treatment of seedlings showed that the expression of PmCBF genes were induced by 2 °C within 30 min, and their expression reached a peak after 8–12 h. In addition, PmCBFa and PmCBFb appeared more sensitive to LT than PmCBFc. However, the exact roles of PmCBF genes in plant cold tolerance need to be further investigated.

Heat or cold priming-induced cross-tolerance to abiotic stresses in plants: key regulators and possible mechanisms

Abstract: Plants growing under field conditions are constantly exposed, either simultaneously or sequentially, to more than one abiotic stress factor. Plants have evolved sophisticated sensory systems to perceive a number of stress signals that allow them to activate the most adequate response to grow and survive in a given environment. Recently, cross-stress tolerance (i.e. tolerance to a second, strong stress after a different type of mild primary stress) has gained attention as a potential means of producing stress-resistant crops to aid with global food security. Heat or cold priming-induced cross-tolerance is very common in plants and often results from the synergistic co-activation of multiple stress signalling pathways, which involve reactive nitrogen species (RNS), reactive oxygen species (ROS), reactive carbonyl species (RCS), plant hormones and transcription factors. Recent studies have shown that the signalling functions of ROS, RNS and RCS, most particularly hydrogen peroxide, nitric oxide (NO) and methylglyoxal (MG), provide resistance to abiotic stresses and underpin cross-stress tolerance in plants by modulating the expression of genes as well as the post-translational modification of proteins. The current review highlights the key regulators and mechanisms underlying heat or cold priming-induced cross-stress tolerance in plants, with a focus on ROS, MG and NO signalling, as well as on the role of antioxidant and glyoxalase systems, osmolytes, heat-shock proteins (HSPs) and hormones. Our aim is also to provide a comprehensive idea on the topic for researchers using heat or cold priming-induced cross-tolerance as a mechanism to improve crop yields under multiple abiotic stresses.

Fusion primer and nested integrated PCR (FPNI-PCR): a new high-efficiency strategy for rapid chromosome walking or flanking sequence cloning

Abstract: Background The advent of genomics-based technologies has revolutionized many fields of biological enquiry. However, chromosome walking or flanking sequence cloning is still a necessary and important procedure to determining gene structure. Such methods are used to identify T-DNA insertion sites and so are especially relevant for organisms where large T-DNA insertion libraries have been created, such as rice and Arabidopsis. The currently available methods for flanking sequence cloning, including the popular TAIL-PCR technique, are relatively laborious and slow.

Plant small heat shock proteins - evolutionary and functional diversity.

Abstract: Small heat shock proteins (sHSPs) are an ubiquitous protein family found in archaea, bacteria and eukaryotes. In plants, as in other organisms, sHSPs are upregulated by stress and are proposed to act as molecular chaperones to protect other proteins from stress-induced damage. sHSPs share an 'α-crystallin domain' with a β-sandwich structure and a diverse N-terminal domain. Although sHSPs are 12-25 kDa polypeptides, most assemble into oligomers with ≥ 12 subunits. Plant sHSPs are particularly diverse and numerous; some species have as many as 40 sHSPs. In angiosperms this diversity comprises ≥ 11 sHSP classes encoding proteins targeted to the cytosol, nucleus, endoplasmic reticulum, chloroplasts, mitochondria and peroxisomes. The sHSPs underwent a lineage-specific gene expansion, diversifying early in land plant evolution, potentially in response to stress in the terrestrial environment, and expanded again in seed plants and again in angiosperms. Understanding the structure and evolution of plant sHSPs has progressed, and a model for their chaperone activity has been proposed. However, how the chaperone model applies to diverse sHSPs and what processes sHSPs protect are far from understood. As more plant genomes and transcriptomes become available, it will be possible to explore theories of the evolutionary pressures driving sHSP diversification.

The genetic architecture of floral traits in the woody plant Prunus mume

Abstract: Mei (Prunus mume) is an ornamental woody plant that has been domesticated in East Asia for thousands of years. High diversity in floral traits, along with its recent genome sequence, makes mei an ideal model system for studying the evolution of woody plants. Here, we investigate the genetic architecture of floral traits in mei and its domestication history by sampling and resequencing a total of 351 samples including 348 mei accessions and three other Prunus species at an average sequencing depth of 19.3×. Highly-admixed population structure and introgression from Prunus species are identified in mei accessions. Through a genome-wide association study (GWAS), we identify significant quantitative traits locus (QTLs) and genomic regions where several genes, such as MYB108, are positively associated with petal color, stigma color, calyx color, and bud color. Results from this study shed light on the genetic basis of domestication in flowering plants, particularly woody plants.

Genome-wide characterization and linkage mapping of simple sequence repeats in mei (Prunus mume Sieb. et Zucc.).

Abstract: Because of its popularity as an ornamental plant in East Asia, mei (Prunus mume Sieb. et Zucc.) has received increasing attention in genetic and genomic research with the recent shotgun sequencing of its genome. Here, we performed the genome-wide characterization of simple sequence repeats (SSRs) in the mei genome and detected a total of 188,149 SSRs occurring at a frequency of 794 SSR/Mb. Mononucleotide repeats were the most common type of SSR in genomic regions, followed by di- and tetranucleotide repeats. Most of the SSRs in coding sequences (CDS) were composed of tri- or hexanucleotide repeat motifs, but mononucleotide repeats were always the most common in intergenic regions. Genome-wide comparison of SSR patterns among the mei, strawberry (Fragaria vesca), and apple (Malus×domestica) genomes showed mei to have the highest density of SSRs, slightly higher than that of strawberry (608 SSR/Mb) and almost twice as high as that of apple (398 SSR/Mb). Mononucleotide repeats were the dominant SSR motifs in the three Rosaceae species. Using 144 SSR markers, we constructed a 670 cM-long linkage map of mei delimited into eight linkage groups (LGs), with an average marker distance of 5 cM. Seventy one scaffolds covering about 27.9% of the assembled mei genome were anchored to the genetic map, depending on which the macro-colinearity between the mei genome and Prunus T×E reference map was identified. The framework map of mei constructed provides a first step into subsequent high-resolution genetic mapping and marker-assisted selection for this ornamental species.