Plant Biotechnology Reports最新文献

Lead (Pb) is one of the most toxic heavy metals (HMs) for plants and the environment. Sweetpotato [Ipomoea batatas (L.) Lam], the sixth most important food crop in the world, is tolerant to various environmental stresses, owing to its high antioxidant capacity. In this study, we selected sweetpotato cultivars showing high tolerance to lead (Pb) for phytoremediation-related applications. Young seedlings of 20 sweetpotato cultivars were treated with 30 mM Pb. Daeyumi (KO-12) and Dahomi (KO-5) were selected as Pb-tolerant and -sensitive cultivars, respectively, based on their photosynthetic activity and growth inhibition index (I₅₀). In the Pb treatment, hydrogen peroxide and malondialdehyde contents of KO-12 were 1.5-fold less than those of KO-5. In addition, KO-12 showed a higher ability to accumulate Pb in roots and leaves than KO-5. Expression levels of four Pb-responsive genes, including the metallothionein gene IbMT1, were higher in the roots and leaves of KO-12 than in those of KO-5. Interestingly, KO-12 showed greater tolerance to high Pb concentrations than sunflower and rapeseed, which have been well-studied for phytoremediation. Our results suggest that sweetpotato is a suitable biomaterial for the phytoremediation of soils contaminated with HMs, including lead, for sustainable agriculture.

Cesium (Cs) toxicity has deleterious effects on plant growth and development. However, the molecular mechanism of the toxic effect of Cs on plants has been poorly understood. To obtain insights into the molecular events occurring in plants under Cs stress, we performed a comparative transcriptomic analysis between control and Cs-treated plants via RNA-seq. We identified 183 differentially expressed genes (141 upregulated and 42 downregulated) under Cs stress (1.5 mM CsCl). Gene ontology (GO) analysis using differentially expressed genes in Cs stress indicated that Cs triggered plant stress signaling pathways like reactive oxygen species (i.e., hydrogen peroxide). Further KEGG and MapMan metabolic pathway analyses revealed that many abiotic/biotic stress signaling pathways were highly induced. In particular, heat shock protein family genes were substantially induced upon exposure to Cs stress. We investigated the root growth of several knockout mutants of heat shock protein family genes and found that heat stress response was compromised in these mutants compared to wild type plants. It suggested that heat shock protein genes including HSP17s, HSP23s, HSP101, and HSFA2 proteins are deployed upon exposure to Cs for plant stress tolerance. Our study provided novel insights into the molecular events occurring in Cs-stressed plants.

Zinc-finger homeodomain transcription factors (ZF-HD TFs) are relatively a small gene family in Arabidopsis involved in plant development and stress response. However, the biological functions of ZF-HD TFs remain largely undiscovered. Here, we aimed to elucidate the evolutionary history and functional role of ZF-HD TFs in other species, by performing phylogenic analysis and domain and motif identification studies in Arabidopsis, sorghum (Sorghum bicolor), and moss (Physcomitrella patens). Forty-two ZF-HD TF proteins were classified into two distinct subfamilies based on the conserved ZF Cys/His-rich dimerization and homeodomain (HD) domains. The phylogenetic tree of proteins was further divided into five groups based on the similarity of sequences, and three distinct motifs were defined in the amino acid sequences. Genetic analysis revealed that the moss PpZF-HD1, Pp3c1_15290, gene partially rescued the amiR zf-HD-79 mutant lines at phenotypic and molecular levels. Subcellular localization studies revealed that moss PpZF-HD1 was localized in the cytosol and nuclei. Phylogenetic analysis and genetic complementation revealed that ZF-HD TFs play functional roles in regulating plant architecture, which is conserved in Arabidopsis, sorghum, and moss. Although our study is only a preliminary exploration into ZF-HD TFs, it provides a novel perspective that will help future researchers better understand the biological role of ZF-HD proteins in plants.

Frogeye leaf spot (FLS), caused by Cercospora sojina, is a threat to soybean cultivation, leading to substantial economic losses. Here, an RNA sequencing analysis was conducted to identify genes associated with the response of wild soybean (Glycine soja) to C. sojina. Differentially expressed genes (DEGs) were identified by comparing the gene expression of C. sojina-inoculated plants with that of non-inoculated plants. A total of 1642 DEGs (790 up-regulated and 852 down-regulated) were identified in C. sojina-inoculated wounded leaves compared with non-inoculated wounded leaves. The DEGs were analyzed for gene ontology and the KEGG pathway to identify the key genes responsible for the response to C. sojina and the corresponding pathways. In GO analysis, ‘Defense response’ was highlighted, while in KEGG analysis, ‘Metabolic pathways’ and ‘Flavonoid biosynthesis’ were emphasized. A total of 67 DEGs were categorized within the 'biotic stress' MapMan category, with ‘Redox state,’ ‘Cell wall,’ and ‘Secondary metabolites’ showing the highest abundance of assigned DEGs. DEGs associated with the phenylpropanoid pathway (GsALDH and GsAOMT-like), cell wall remodeling (GsPME12), and reactive oxygen species (GsGSTUs), were identified in plants inoculated with C. sojina compared to non-inoculated plants. Additionally, Gs2MF3OR-like (encodes an enone oxidoreductase) and Gsα-DOX1-like (involved in oxidative stress) also participated in the response of wild soybean to the disease. Our results suggest potential C. sojina-resistant genes that could serve as targets for further functional characterization, as well as for soybean molecular breeding programs aimed at improving FLS resistance.

Pak-choi (Brassica rapa ssp. chinensis) is a popular vegetative crop in southern China, East Asia, and Southeast Asia. Owing to the threat of climate change, rapid breeding strategies for vegetable cultivars that are tolerant to abiotic and biotic stresses are required. Thus, the rapid fixation of useful agronomic traits using doubled haploid technology is urgent. The haploid-inducer gene is key to doubled haploidization. Two known CENH3 and pPLAIIγ genes, in which altered or partially deleted forms lead to haploid induction, were selected, and direct editing of Pak-choi CENH3 and pPLAIIγ genes (BcCENH3 and BcpPLAIIγ) was conducted using an Agrobacterium-mediated CRISPR/Cas9 system. First, BcCENH3 and BcpPLAIIγ genes were characterized by analyzing the spatial expression patterns and subcellular localization. The CENH3 expression levels in carpels and pPLAIIγ in various parts of Pak-choi flowers were higher than those of other parts. BcCENH3 and BcpPLAIIγ proteins targeted in the nucleus and plasma membrane, respectively. Whole plants were successfully regenerated from the shoot apical meristem (SAM) regions of Pak-choi seedlings using the optimized procedure and culture conditions. The regeneration results of SAM explants after Agrobacterium-mediated transformation of constructs expressing CRISPR/Cas9 and BcCENH3 or BcpPLAIIγ sgRNAs confirmed four independent BcCENH3-targeted transgenic lines with 2.1%, 1.8%, 1.8%, and 1.7% INDEL frequencies, and three independent BcpPLAIIγ-targeted transgenic lines with 24.5%, 33.7%, and 33.0% INDEL frequencies. Thus, our results suggested the possibility of developing transgenic Pak-choi lines by applying the CRISPR/Cas9 genome editing technology to BcCENH3 and BcpPLAIIγ as two haploid-inducer genes.

Plants are among the many creatures that have benefited from the widespread application of the CRISPR-associated Cas system as a genome-editing tool for investigating gene function, identifying disease, and enhancing agricultural yields. Although the CRISPR/Cas systems for DNA editing are widely employed, post-transcriptional manipulation of RNA remains difficult despite the prevalence of Cas9. Type VI CRISPR/Cas systems, which were recently found, allow for precise RNA editing without permanently affecting the genome. Cas13d has been put to good use in RNA-related studies across a wide range of RNA knock-down, and RNA detection without affecting DNA. Regulation of cas13d specificity and activity helps to avoid the off-target effects and immune responses in plants. Cas13d as highly efficient RNA-targeting tools for the virus resistance, gene function studies, disease diagnostics, and crop improvement in plants. However, CRISPR/Cas13d applications in plant RNA biology are just getting started. This article discusses how RNA editing tools derived from the CRISPR/Cas13d system are currently being used and where they may be used in the future for plant research.

Abstract

Tomato (Solanum lycopersicum L.) crop is well-known for its versatility worldwide and is also recognized as model species used extensively for various genetic studies. The aim of this research was to investigate both inter and intra-genetic diversity present among various tomato genotypes. This investigation was carried out through a comprehensive analysis encompassing morphological observations, biochemical assessments, and the utilization of SSR markers. A total of 15 discrete agro-morphological traits and six biochemical traits were undertaken in the current study for evaluating the analysis of variance, genetic parameters and correlation. The analysis of variance indicated significant differences across genotypes for all 15 agro-morphological traits and 6 biochemical traits tested, indicating that the experimental material included considerable variability. Morphological clustering divided the genotypes into 2 clusters and the genotype wise distance matrix was obtained to identify the most diverse genotypes. PCA analysis was conducted to understand the directive relation of traits and magnitude of variability contributed by them. SSR profiling with 24 primers identified 44 alleles with 1.83 as mean number of alleles/SSR with an average PIC value of 0.31. Structure analysis revealed two sub-populations (K = 2). The AMOVA indicated that 98% of the total variation was present within populations. This study presents a roadmap for composing future breeding strategies for integrating desirable traits in novel tomato lines that combine robustness and nutritive value.

Some edible Leguminous are toxic when raw, and the Chinese are particularly fond of beans, so Leguminous poisoning is very common in China. Rapid and accurate identification of poisoned species and determination of their toxic components would better assist physicians in treating patients. However, traditional morphology-based identification methods possess many limitations. DNA barcoding technique is a new species identification technique developed in recent years, which is expected to make up for the shortcomings of traditional morphological identification. In this study, a comprehensive evaluation system based on DNA barcoding and ELISA kits was attempted. A total of 30 Leguminous toxic plants were collected, involving 9 genera and 10 species. We used simulated gastric fluid (SGF) to simulate the human gastric environment. Three markers (rbcL, trnH-psbA, and ITS) were amplified and sequenced for all untreated and 15 mock-digested samples. The validity of DNA barcoding for species identification was assessed using the Basic Local Alignment Search Tool (BLAST) method and the tree construction method. The levels of three toxic components (saponin, phytoagglutin and trasylol) were determined in all samples using ELISA kits. The amplification success rate of all three regions was high (rbcL 96.67%, trnH-psbA 100%, and ITS 100%), but the sequencing of the trnH-psbA region was less satisfactory (66.67%), and SGF had a significant impact on the sequencing of the ITS region (After 40 min of SGF treatment, the sequencing success rate decreased by 46.67%). The samples from different species and origins contained different levels of toxic components, and the levels of all three substances decreased significantly after undergoing SGF digestion. After 1 h of SGF treatment, the saponin content decreased to 0–8.60% in untreated content (PHA decreased to 8.62–36.88%, trasylol decreased to 4.70–47.06%). The current results suggest that DNA barcoding has great potential for rapid identification of Leguminous poisoning in clinical settings. Toxins are probably not detectable in the patient for longer periods of poisoning. We recommend DNA barcoding technology as a first step for rapid screening and combined with toxin analysis for clinical diagnosis.

The WRKY transcription factor family plays a key role in plant growth and development, hormone signaling, and resistance to environmental stress. In this study, we investigated the gene sequence, subcellular localization, and response pattern of a member of the WRKY transcription factor family to reveal its protein structure and involvement in the resistance signaling pathway.The BsWRKY51 gene was cloned by RT-PCR, and the structural characteristics of its encoded protein WRKY51 were analyzed by bioinformatics. The vector was next transiently transformed into tobacco to analyze the subcellular localization, and real-time fluorescence quantitative PCR was performed to analyze the changes in the expression pattern of BsWRKY51. The BsWRKY51 gene has a coding sequence (CDS) length of 987 bp.The respective unstable hydrophilic protein BsWRKY51 is localized in the nucleus. It most closely related to the WRKY protein of Dendrobium catenatum in the Orchidaceae family. Fluorescence quantitative PCR results showed that the BsWRKY51 expression in the leaves was significantly higher than that in the roots, stems, and pseudobulbs of Bletilla striata seedlings. Under the conditions of salt and drought stress, the BsWRKY51 expression gradual increased and then a slightly decreased, and under salicylic acid (SA) treatment, the expression of BsWRKY51 showed an overall decreasing trend.The BsWRKY51 gene of Bletilla striata may play an important regulatory role in its salt and drought stress responses. Our present findings provide the foundation for elucidating the mechanisms of salt and drought tolerance in Bletilla striata and for breeding new varieties.

CRISPR/Cas9-based targeted gene editing has emerged as a versatile tool for deciphering gene function and improving traits in plants. However, this technique has not been applied to Zoysia japonica, a prominent warm-season turfgrass widely used for green spaces. Leaf senescence, a vital process affecting crop quality, occurs in Z. japonica during late growth, diminishing its aesthetic value and performance. In this study, we adeptly employed CRISPR/Cas9-mediated gene editing to create Z. japonica exhibiting delayed leaf senescence by targeting the ZjEIN2 gene, a crucial regulator of ethylene-mediated senescence. Precise gene editing, which generated knockout mutations in ZjEIN2, led to delayed leaf senescence in both dark and ethylene treatment conditions. This provided strong evidence for ZjEIN2’s role in leaf senescence regulation. These findings highlight the potential of CRISPR/Cas9-mediated gene editing as a biotechnological strategy to enhance anti-senescence traits in Z. japonica and potentially other crops. This study carries significant implications for sustainable agriculture and turfgrass management, offering promising avenues for future applications and research.