Journal of Integrative Plant Biology最新文献

A stable and efficient transformation system is crucial for functional genomics and trait improvement in soybean. This study developed a tissue culture based genetic transformation system incorporating dual selection (Spectinomycin and RUBY). This system significantly enhances transformation efficiency, shortens the transformation cycle, and demonstrates broad genotype independence, providing a powerful tool for soybean research and breeding.

Rice is a staple food for more than half of the world's population, particularly in Asia. Cadmium (Cd) contamination in rice poses serious risks to human health through the food chain. Understanding the mechanisms governing Cd uptake, translocation, and tissue distribution, as well as its interaction with essential metals such as iron (Fe), zinc (Zn), and manganese (Mn), is critical for improving rice safety. Over the past two decades, key transporters involved in Cd and micronutrient homeostasis have been identified, providing insights into their crosstalk and competition. In this review, we summarize current knowledge on Cd and essential metal transport in rice and discuss the challenges and trade-offs in limiting Cd accumulation while maintaining plant growth and micronutrient balance, highlighting strategies for developing rice varieties with reduced Cd content and enhanced food safety.

3D genome editing reconfigures chromatin loops to fine-tune gene expression for coordinated improvement of multiple crop traits.

Low temperature is a critical abiotic stress constraining rice production by impairing seed germination, seedling establishment, and reproductive development. Rice has developed a multifaceted regulatory system for cold tolerance through physiological adaptation and coordinated gene expression networks. Recent advances in quantitative trait locus (QTL) mapping and functional gene discovery have substantially elucidated the genetic basis of this complex trait. Molecular breeding strategies, including marker-assisted selection (MAS) and genome editing, hold significant promise for the development of novel cold-tolerant rice varieties. This review comprehensively summarizes the current knowledge on physiological responses, molecular mechanisms, and cold adaptation strategies in rice under low-temperature conditions. Specifically, we synthesize the breeding potential of cold-tolerant genes and discuss their application strategies in biological breeding, providing a strategic framework to advance the genetic improvement of cold tolerance in rice.

Ceramide synthases (CerSs) are central to sphingolipid biosynthesis and influence plant development and defense responses. However, how CerS activity is regulated in plants remains unclear. Here, we discovered that LAG ONE HOMOLOG 2 (LOH2), the sole long-chain CerS in Arabidopsis (Arabidopsis thaliana), is post-translationally regulated by the ubiquitous kinase casein kinase 2 (CK2). CK2 interacts with LOH2 and phosphorylates serine residues S289 and S291 within its C-terminal region. We mutated these two serines to alanines and expressed the resulting non-phosphorylatable LOH2 variant in transgenic plants and protoplasts. We found that phosphorylation enhances LOH2 enzymatic activity, partially by increasing its substrate-binding affinity, but concurrently promotes LOH2 polyubiquitination and degradation via the 26S proteasome without affecting its subcellular localization. Plants expressing a non-phosphorylatable LOH2 variant showed diminished cell death, reduced C16 ceramide biosynthesis and salicylic acid (SA) accumulation, and compromised resistance to the fungal toxin Fumonisin B1 and the bacterial pathogen Pseudomonas syringae. Pathogen infection induces LOH2 phosphorylation, promoting C16 ceramide accumulation, SA production, and resistance gene expression. Collectively, our findings demonstrate that CK2 fine-tunes LOH2 enzymatic activity and stability, and thus the production of long-chain ceramides through phosphorylation, thereby regulating plant development and defense responses.

The highly transformable maize inbred line LH244 represents an attractive model for gene discovery and genome engineering. However, the lack of a high-quality genome assembly has limited its utility in functional genomics research. Here, we present a 2.29 Gb near-complete assembly of the LH244 maize genome, with an overall base accuracy of 99.998%. Except for five gaps associated with super-long thymine–adenine–guanine (TAG) repeat arrays, all the genome sequences were assembled from telomere to telomere (T2T). Comparative analysis revealed high genetic similarity between LH244 and B73, including 80.06% genome-wide synteny and 90.92% of genes nearly identical. The LH244 genome was also compared with the complete Mo17 genome and revealed extensive intraspecific genomic variations. A total of 14 megabase-scale structural variations (SVs) were identified, including a 3.15 Mb insertion, harboring 95 genes, within the 45S rDNA array of LH244 but not in the Mo17 genome. In addition, there were five knob arrays, with an average size of 21.76 Mb and the longest of 38.70 Mb, only existing in the LH244 genome. Despite the substantial variation in knob abundance, knob-6S and knob-8L were highly conserved between LH244 and Mo17, showing strong synteny and sequence identity, as well as consistent insertion patterns of genes and transposable elements (TEs). Overall, our study provides a near-complete reference genome of an important transformable maize germplasm, which will serve as a much-needed resource for functional genomics and genome editing of maize.

In poplar trees, a molecular switch involving phytochrome B and PHYTOCHROME-INTERACTING FACTOR 4 responds to cool temperatures by keeping growth active, preventing premature dormancy. This mechanism, which differs from that in Arabidopsis, helps trees adapt to cool summers and ensures survival in seasonal environments.

The assembly of functional biological materials requires precise control over the synthesis and deposition of their constituent polymers. In plants, specialized cells gain exceptional strength from their secondary cell walls (SCWs), though the mechanisms ensuring the coordinated production of SCW components remain poorly understood. Using cotton fiber as a model for massive cellulose deposition, we uncover a multi-tiered transcriptional cascade involving the R2R3-MYB transcription factor GhMYB44. We show that GhMYB44 functions as a positive regulator that directly activates the pivotal NAC factor, GhFSN43, which in turn commands key cellulose synthesis genes, establishing a complete regulatory module from an upstream MYB to downstream structural genes. Crucially, we reveal that this entire pathway is potentiated at two distinct nodes through protein-protein interactions: an upstream GhMYB44-GhREV5 complex enhances the initial signal, while a downstream GhFSN43-GhFSN1 complex functions cooperatively to strengthen downstream transcriptional activation. Our findings suggest that GhMYB44 participates in a multi-tiered regulatory module where transcriptional output is enhanced by layered synergistic protein-protein interactions. This work clarifies a key regulatory pathway controlling SCW biosynthesis and offers novel targets for improving cotton fiber quality.

Wild perennial sister species Medicago archiducis-nicolai (rhizomatous/alpine) and M. ruthenica (non-rhizomatous/xeric) constitute vital genetic resources for forage improvement. To decode the genomic basis of their contrasting trait and habitat adaptation, we generated chromosome-scale genome assemblies, resequenced 128 individuals, profiled transcriptomes under cold/heat stress, and functionally validated causal alleles. We demonstrate that structural variations (SVs)—particularly gene duplications—are primary drivers of rhizome formation and alpine/xeric adaptation. Further, pervasive presence–absence SVs (PAVs) in noncoding regulatory regions underpin divergent allele-specific expression governing rhizome development and stress responses. Crucially, these regulatory PAVs induce contrasting expression patterns during trait development and stress adaptation. Our findings reveal a dual mechanism whereby coding and regulatory SVs convergently orchestrate phenotypic innovation and ecological specialization in sister species, offering valuable genomic resources for legume evolution studies and alfalfa breeding.