The Plant Journal最新文献

Bamboo is known for its fast growth, and non-structural carbohydrates (NSCs) play a pivotal role in bamboo's fast growth. Despite extensive research on bamboo's growth, the role of NSCs, especially the underlying molecular regulatory mechanisms, in bamboo's fast growth remains largely unexplored. By studying growth patterns in various bamboo species, it was found that NSCs are transferred from mature bamboo to young shoots, facilitating their fast growth. This review explores NSCs in bamboo, covering their content, distribution, storage, and enzyme activities. It examines NSCs' physiological roles, including mobilization, transport, and growth facilitation, and discusses potential molecular regulatory mechanisms. It also summarizes the gene expression patterns involved in NSC synthesis and metabolism during bamboo's fast growth. NSCs regulate genes related to sugar transport, cell division, energy metabolism, and cell wall synthesis, thereby regulating bamboo's fast growth. NSCs interact with hormone signaling networks. Lastly, winter drought and cold stress stimulate NSC storage and transport. These stressors potentially serve as signals or prerequisites for NSC transport and accumulation. In general, this review summarizes the research progress on NSC transport from bamboo and its impact on bamboo's fast growth, providing a foundation for enhancing understanding and investigation of bamboo's fast growth mechanisms.

To meet the nutritional needs of the rising human population, genetic variants are necessary for the breeding of new cultivars. Rice (Oryza sativa L.) is a staple food for over half of the world's population. Here, we developed a new rice genetic resource, the NARO Open Rice Collection (NRC) with high-resolution genome data. NRC consists of 623 accessions, and approximately 200 accessions are categorized into three major subgroups, categorized as Indica, Japonica, and Aus. In this study, we performed genome-wide association studies (GWAS) for rice heading date, seed shape, and seed ionome using the NRC. Well-known genes related to heading date and seed shape were detected by GWAS using the NRC accessions. Therefore, we concluded that our new rice collection is suitable for GWAS. In addition, GWAS with each subgroup was advantageous for the detection of particular genes. Finally, we performed GWAS for seed ionome with the aim of improving the nutritional properties of rice, as essential minerals for humans, such as iron (Fe) and zinc (Zn), are not sufficient in rice seeds. Our study revealed that OsATL31, a likely ubiquitin E3 ligase, was involved in the control of Fe and Zn contents in seeds.

The process of male reproductive development in plants involves a series of biological events. These events are governed by complex transcriptional regulatory networks, which are composed of numerous transcriptional regulatory components (TRCs). ABERRANT MICROSPORE DEVELOPMENT1 (AMD1) is a recently identified TRC that is essential for rice pollen production. Nevertheless, the molecular roles of AMD1 in regulating rice pollen production are largely unknown. Here, we demonstrate that AMD1 is directly activated by OsMYB103 as a genetic downstream target during rice pollen development. Interestingly, several direct target genes of OsMYB103, including AMD1 itself, exhibit a more drastic expression down-regulation in the double mutant of AMD1 and OsMYB103 than in the single mutants. Our ongoing in vivo and in vitro experiments consistently indicate that AMD1 physically interacts with OsMYB103, thereby facilitating the activation of OsMYB103 on its target genes, possibly through the recruitment of the RNA polymerase II complex component OsTFIIF2-2. Our findings collectively suggest that the transcriptional cascade composed of OsMYB103 and AMD1 precisely regulates rice male fertility through a feed-forward loop mechanism, offering new insights into the role of AMD1 within the transcriptional regulatory network governing rice pollen development.

Plant immune receptors and their natural variations play a central role in combating disease-causing pathogens. These immune receptors include intracellular nucleotide-binding leucine-rich repeat (LRR) receptors (NLRs) and cell-surface pattern recognition receptors (PRRs) that can be further classified as receptor-like proteins (RLPs) and receptor-like kinases (RLKs). Although the NLRome has been characterized, the repertoire and extent of diversity of PRRome remain undetermined in rice. In this study, we examined the diversity of immune receptor genes using high-quality genomes of 309 rice accessions from 8 species within the genus Oryza. A total of 376 310 immune receptor genes were identified, including 149 592 NLR-coding genes and 226 718 PRR coding genes. Shannon entropy analysis revealed a set of immune receptors that display significant intra-species and inter-species diversity in rice. In general, RLPs are more variable than RLKs, while NLRs and LRR-RLPs are more variable than LRR-RLKs. Additionally, NLR and PRR genes exhibit contrasting shoot/root expression patterns, with NLRs generally skewed towards root expression. Furthermore, we found that the size of the LRR-RLK gene families correlates with local annual precipitation, suggesting a stronger selection pressure on LRR-RLK genes in rice accessions grown under wet conditions than dry conditions. In sum, this pan-genomic analysis not only reveals the extensive diversity of the immune receptor repertoires in rice but also provides potential target genes for improving disease resistance in rice.

Plants make structurally diverse triterpenoids for their physiological needs, which have shown numerous therapeutic applications. Arjuna tree (Terminalia arjuna) produces bioactive oleanane (β-amyrin-derived) triterpenoids arjunic acid, arjungenin, and arjunolic acid, and the respective C28-O-glucopyranosyl esters arjunetin, arjunglucoside I, and arjunglucoside II. Arjunic acid and arjunetin are the major oleananes in bark, while arjunolic acid and arjunglucoside II are found in minor levels. Although arjungenin was detected at a considerable level, arjunglucoside I was found only at a trace level, suggesting selective biosynthesis and/or accumulation of triterpenoid glucosyl esters in bark. However, the enzyme contributing to triterpenoid C28-O-glucosylation was not characterized. We mined RNA-sequencing data and identified UDP-glucosyltransferase (UGT) transcripts that were enriched in the bark transcriptome. Further, biochemical screening of UGTs identified UGT73FB1, which catalyzed triterpenoid C28-O-glucosylation in a scaffold-selective manner. Recombinant UGT73FB1 produced in Escherichia coli or Nicotiana benthamiana formed arjunic acid and arjunolic acid C28-O-glucopyranosyl esters arjunetin and arjunglucoside II, but not arjungenin C28-O-glucopyranosyl ester (arjunglucoside I). Interestingly, UGT73FB1 showed better activity using oleananes than ursanes (α-amyrin-derived), but it did not show C28-O-glucosylation activity using various lupane triterpenoids (lupeol-derived). Overall, the spatial patterns of UGT73FB1 transcript expression and triterpenoid accumulation and scaffold-selective activity of UGT73FB1 suggested a major role of UGT73FB1 in the biosynthesis of C28-O-glucopyranosyl esters in arjuna. Moreover, UGT73FB1 co-expression with β-amyrin synthase and triterpenoid C2, C23, and C28 hydroxylases/oxidases led to complete reconstruction of the arjunglucoside II pathway in N. benthamiana, suggesting the utility of arjuna enzymes for the biosynthesis of rare triterpenoid glucopyranosyl esters in heterologous hosts.

Arbuscular mycorrhizal (AM) symbiosis enhances nutrient acquisition and stress resilience in plants, yet the genetic mechanisms regulating this interaction in wheat remain poorly understood. This study explores the variation in AM colonization rates across a diverse set of wheat varieties and aims to identify key genes that regulate the wheat–AM symbiosis. Understanding these molecular mechanisms is crucial for improving nutrient uptake efficiency and stress resistance in wheat breeding programs. Here, we conducted a genome-wide association study (GWAS) of 291 wheat varieties and integrated transcriptomic data to identify TaLAC129, a laccase (LAC)-encoding gene, as a critical negative regulator of AM colonization in wheat roots. Overexpression of TaLAC129 significantly increased root LAC activity and lignin content, concurrently suppressing AM colonization. While this suppression reduced nitrogen (N), phosphorus (P), and potassium (K) uptake in stems, leaves, and glumes, it markedly enhanced nutrient utilization efficiency (NUE) in grains. Furthermore, TaLAC129 overexpression improved agronomic traits, including grains per panicle, 1000-grain weight, and overall yield. Our findings reveal the dual role of TaLAC129 in balancing AM symbiosis and nutrient allocation, offering a novel genetic target for breeding wheat varieties with improved yield and nutrient efficiency. This study provides critical insights into the molecular coordination between symbiotic trade-offs and agricultural productivity in cereal crops.

Flowering is an important developmental transition from the vegetative to the reproductive phase in plants. The role of histone modifications in the regulation of flowering time is well documented; however, their role in Chinese cabbage remains unclear. In the present study, we investigated a Chinese cabbage late-bolting mutant, M1407, which displayed a late-bolting time phenotype after vernalization. MutMap, kompetitive allele-specific PCR (KASP), and RNA interference (RNAi) analyses demonstrated that BrSWN, which encodes a catalytic subunit of the Polycomb repressive complex 2 (PRC2), mediates the flowering time in Chinese cabbage. BrSWN was functionally conserved and localized to the nucleus. Both BrSWN and Brswn interacted with BrVRN2 to form PRC2-like complexes. The BrSWN mutation decreased the global histone H3 lysine 27 trimethylation (H3K27me3) level and impaired the enrichment of H3K27me3 in the regions of flowering repressors, BrFLC2 and BrFLC3. This study demonstrates that BrSWN mediates the regulation of bolting time modulated by H3K27me3 deposition, providing insights into the epigenetic mechanisms regulating flowering time in Chinese cabbage.

The coat protein (CP) of the melon necrotic spot virus (MNSV) is a multifunctional factor localized in the chloroplast, mitochondria, and cytoplasm, playing a critical role in overcoming plant defenses such as RNA silencing (RNAi) and the necrotic hypersensitive response. However, the molecular mechanisms through which CP interferes with plant defenses remain unclear. Identifying viral–host interactors can reveal how viruses exploit fundamental cellular processes and help elucidate viral survival strategies. Here, we employed a TurboID-based proximity labeling approach to identify interactors of both the wild-type MNSV CP and a cytoplasmic CP mutant lacking the dual transit peptide (ΔNtCP). Of the interactors, eight were selected for silencing. Notably, silencing MAP4K SIK1 and NbMAP3Kε1 kinases, and a splicing factor homolog NbSMU2 significantly reduced MNSV accumulation, suggesting a proviral role for these proteins in plants. Yeast two-hybrid and bimolecular fluorescence complementation assays confirmed the CP and ΔNtCP interaction with NbSMU2 and NbMAP3Kε1 but not with NbSIK1, which interacted with NbMAP3Kε1. These findings open up new possibilities for exploring how MNSV CP might modulate gene expression and MAPK, thereby facilitating MNSV infection.