Plant Biotechnology Journal最新文献

Clubroot, a severe soil-borne disease caused by Plasmodiophora brassicae, poses a severe threat to global production of Brassicaceae oilseed crops and vegetables. To date, there has been a serious lack of clubroot-resistant germplasms in Brassica napus (AACC), necessitating the urgent development of novel disease-resistant germplasm. We present a high-quality genome assembly of an artificially synthesised allotetraploid Raphanobrassica (RRCC), which exhibits broad-spectrum immunity to diverse P. brassicae pathotypes. Using a sesquidiploid RACC as a genetic bridge, we developed B. napus-R. sativus (AACC-R) monosomic addition lines and mapped a major clubroot resistance (CR) locus on chromosome R5. Comparative genomic analysis identified 30 candidate CR genes in this region. Notably, overexpression of CRR5.5.11, which encodes a receptor-like protein, via hairy root transformation conferred significant resistance in susceptible B. napus. Evolutionary and functional analyses revealed conserved homologues of CRR5.5.11 in diploid Isatis tinctoria and triploid turnip ECD04. Furthermore, the ECD04 allele CRA3.2.2 also conferred clubroot resistance, indicating that CRR5.5.11 and CRA3.2.2 have originated from the same diploid ancestor. Our study elucidates the genetic and evolutionary basis of clubroot resistance in Raphanobrassica, providing novel germplasm, gene resources and theoretical insights for clubroot-resistance breeding in rapeseed and other Brassicaceae crops.

Ethylene plays a crucial role in fruit ripening and is perceived by specialised receptor proteins embedded in the endoplasmic reticulum (ER) membrane. As an ethylene antagonist, 1-methylcyclopropene (1-MCP) binds to these receptors and delays papaya ripening, but improper use can cause ripening disorders. The expression of CpERS1 and CpERF-WRI1 is markedly upregulated during ripening yet is suppressed by inappropriate 1-MCP treatments. Similar ripening disorders and expression patterns of CpERS1 and CpERF-WRI1 were observed in immature, chilled and heat-stressed papaya fruits, indicating that these genes may play key roles in ripening disorder. CpERF-WRI1 binds to and activates the CpERS1 promoter both in vitro and in vivo. Transient overexpression of CpERF-WRI1 in papaya and ectopic expression in tomato accelerated fruit ripening, increased CpERS1 expression and upregulated ripening-related pathways, whereas virus-induced gene silencing (VIGS) of CpERF-WRI1 in papaya delayed ripening and downregulated those pathways. Similarly, overexpressing CpERS1 in papaya and tomato accelerated ripening and boosted the expression of ripening-associated genes, while VIGS-mediated silencing of CpERS1 delayed ripening and suppressed these genes. Together, these results indicate that CpERF-WRI1 regulates CpERS1 expression and modulates ethylene sensing within the system II ethylene signalling pathway to control papaya ripening.

Efficient purification remains a key technical challenge affecting the recovery efficiency of recombinant proteins in plant-based systems. Complex metabolites, particularly polyphenols, often cause recombinant protein aggregation during purification. In this study, we identified two key polyphenol oxidase genes, PPOa and PPOb from Nicotiana benthamiana, as responsible for these effects. Using CRISPR-Cas9, we generated two ppoa;ppob double knockout lines that significantly improved the purification of virus surface proteins like SARS-CoV-2 Spike trimer and influenza HA trimer. These lines showed reduced polyphenol-protein interactions, minimised aggregation, and higher purification yields. Our work establishes a clean, high-efficiency N. benthamiana chassis for scalable recombinant protein production.

High temperature has posed significant challenges to global agriculture, markedly leading to reduced fertility and yield losses in tomato (Solanum lycopersicum). Therefore, thermotolerance-conferring genes and loci are needed to further improve cultivated tomatoes. Here we identified an E3 ubiquitin ligase SlRNF185, containing a C3HC4-type RING-HC domain, that confers tomato pollen thermotolerance. As a predominant ubiquitination member, SlRNF185 could degrade the SlVPS29 protein induced by heat stress to enhance thermotolerance. Mechanistically, we found that a heat shock transcription factor SlHSFA7 dramatically activates the expression of SlRNF185 under heat stress and acts as a positive regulator of tomato pollen thermotolerance. Collectively, our findings reveal that a SlHSFA7-SlRNF185 genetic module regulates ubiquitination-mediated degradation of SlVPS29 under heat stress, providing the strategy for breeding thermotolerance tomato varieties.

Amino acids serve as fundamental building blocks and signalling molecules in plants, orchestrating stress adaptation mechanisms against diverse biotic and abiotic environmental challenges. However, the mechanism by which plants alter their nutrient metabolism processes to coordinate nitrogen use efficiency (NUE) and salt tolerance remains elusive. Here, we identified a Lysine-Histidine-type transporter 5 (LHT5) gene through genome-wide association studies (GWAS) that enhances NUE via amino acid accumulation regulation. Further research showed that OsLHT5 also confers salt tolerance in rice by promoting proline biosynthesis through transcriptional upregulation of OsP5CS1 and OsP5CS2 genes, thereby increasing cellular proline levels for osmotic adjustment. Notably, we identified a functionally critical 30-bp deletion in the OsLHT5 coding region, designated as the elite haplotype LHT5^HapA, which substantially enhances amino acid transport capacity and consequently improves both NUE and salt tolerance. Functional validation demonstrated that overexpression of LHT5^HapA significantly increases amino acid content, nitrogen accumulation, grain yield and salt stress tolerance compared to the wildtype allele. This study establishes a novel molecular framework linking amino acid transport to the coordination of nutrient utilisation and stress tolerance, offering valuable genetic resources and breeding strategies for developing climate-resilient rice cultivars with enhanced productivity under both optimal and saline conditions.

Promoter engineering holds immense potential for fine-tuning gene expression and optimising agronomic traits, yet conventional genome-editing tools face limitations in precision, scalability, and risk mitigation. Here, we develop Prime Editing-mediated Promoter Engineering (PEPE), a DSB-free platform integrating bidirectional Protospacer adjacent motif (PAM) recognition (NGG/CCN) with combinatorial duo-pegRNA strategies to achieve tiled, overlapping deletions across entire plant promoters. Applying PEPE to the 1.8-kb rice D53 promoter, we generated a mutant library with stepwise deletions. Edited alleles showed stable inheritance, and dual-method validation confirmed the precision at junctions. Quantitative profiling revealed functional modularity: core-region deletions suppressed D53 expression by 70%-85%, while a distal deletion (D53-G9C10) paradoxically upregulated transcription 2.2-fold, uncovering a cryptic repressor element. Phenotypic variation corresponded with transcriptional changes, establishing a direct link between cis-regulatory diversity and agronomic traits. By circumventing DSBs and enabling kilobase-scale CRE manipulation, PEPE establishes a robust framework for decoding promoter logic and accelerating trait pyramiding in crops. This study advances plant genome editing by merging precision with scalability, offering transformative potential for breeding climate-resilient, high-yield cultivars.