Lesion mimic mutants refer to a class of mutants that naturally form necrotic lesions similar to allergic reactions on leaves in the absence of significant stress or damage and without being harmed by pathogens. Mutations in most lesion mimic genes, such as OsACL-A2 and OsSCYL2, can enhance mutants’ resistance to pathogens. Lesion mimic mutants are ideal materials for studying programmed cell death (PCD) and plant defense mechanisms. Studying the genes responsible for the rice disease-like phenotype is of great significance for understanding the disease resistance mechanism of rice. In this paper, the nomenclature, occurrence mechanism, genetic characteristics, regulatory pathways, and the research progress on the cloning and disease resistance of rice lesion mimic mutant genes were reviewed, in order to further analyze the various lesion mimic mutants of rice. The mechanism lays a theoretical foundation and provides a reference for rice breeding.

Clathrin‐mediated vesicle trafficking (CMVT) is a fundamental process in all eukaryotic species, and indispensable to organism's growth and development. Recently, it has been suggested that CMVT also plays important roles in the regulation of plant immunity. However, the molecular link between CMVT and plant immunity is largely unknown. SCY1‐LIKE2 (SCYL2) is evolutionally conserved among the eukaryote species. Loss‐of‐function of SCYL2 in Arabidopsis led to severe growth defects. Here, we show that mutation of OsSCYL2 in rice gave rise to a novel phenotype—hypersensitive response‐like (HR) cell death in a light‐dependent manner. Although mutants of OsSCYL2 showed additional defects in the photosynthetic system, they exhibited enhanced resistance to bacterial pathogens. Subcellular localisation showed that OsSCYL2 localized at Golgi, trans‐Golgi network and prevacuolar compartment. OsSCYL2 interacted with OsSPL28, subunit of a clathrin‐associated adaptor protein that is known to regulate HR‐like cell death in rice. We further showed that OsSCYL2–OsSPL28 interaction is mediated by OsCHC1. Collectively, we characterized a novel component of the CMVT pathway in the regulation of plant immunity. Our work also revealed unidentified new functions of the very conserved SCYL2. It thus may provide new breeding targets to achieve both high yield and enhanced resistance in crops.

Aphelenchoides besseyi (A. besseyi), a seed-borne parasitic nematode, is the causal agent of rice white tip disease (RWTD), which may result in a drastic loss of rice yield. Seed treatments are currently considered to be the most effective means of preventing the spread of RWTD. Therefore, the rapid, highly specific, and accurate detection of A. besseyi from rice seeds is crucial for the surveillance, prevention, and control of RWTD. Here, we describe a novel detection assay that combines recombinase polymerase amplification (RPA) and CRISPR/Cas12a to detect A. besseyi (termed RPA-Cas12a-Ab), with a low limit of detection (LOD) of 1 copy/μl of plasmid or 1:10⁷ diluted DNA extracted from individual nematodes. To improve the user-friendliness, lateral flow strip assay (LFA) was adopted to visualize the detection result. The LOD of the RPA-Cas12a-Ab LFA assay was 1,000 copies/μl plasmid or 1:10 diluted DNA extracted from individual nematodes. The assay developed in this study was able to identify A. besseyi in 45 min with high accuracy and sensitivity without cross reaction with three closely related non-A. besseyi species. Thus, RPA-Cas12a-Ab is a rapid, sensitive, and specific detection system that requires no sophisticated equipment and shows promise for on-site surveillance of A. besseyi.

Fusarium fujikuroi is the primary causal agent of rice bakanae disease, which can lead to substantial yield losses. Developing a rapid, highly specific, and accurate method for detecting F. fujikuroi is crucial for effective surveillance, prevention, and control of rice bakanae disease. In this study, a novel detection assay, RPA-Cas12a-F, was developed by integrating recombinase polymerase amplification (RPA) and Cas12a for the detection of F. fujikuroi. This assay demonstrated a limit of detection (LOD) of 1 copy/μL of reference plasmid or 0.1 fg/μL of F. fujikuroi genomic DNA (gDNA). Furthermore, to enable on-site detection, the RPA-Cas12a technique was combined with a lateral flow strip (LFS) for visual readout, thereby developing the RPA-Cas12a-LFS assay. The LOD of the RPA-Cas12a-LFS assay was 1000 copies/μL of plasmid or 10 fg/μL of F. fujikuroi gDNA. The RPA-Cas12a-based assays developed in this study enable rapid, highly accurate, sensitive, and specific detection of F. fujikuroi, making them a promising tool for on-site detection without the need for expensive equipment and time-consuming methodologies.

Understanding the genetic basis of elite rice varieties is conducive to the strategic utilization of genetic resources in modern breeding programs. To elucidate the genetic component and transmission across pedigrees, we investigated two elite inbred japonica varieties, Huruan1212 (HR1212) and Hugeng137 (HG137), through whole-genome sequencing with an average depth of 38.2× and pedigree analysis. We identified specific SNPs and enriched pathways underlying HR1212's excellent eating and cooking quality and HG137's stress resistance. Genomic scans traced the contributions of founder parents Xiushui04 and Wuyugeng3, revealing transmission patterns of favorable alleles across generations. Notably, the shared identity-by-descent (sIBD) segments of the two pedigrees overlapped by 74 Mb, total formed 118.42 Mb of conserved genetic segments, with validation in other founder-derived lines. This research provides valuable insights for utilizing founder parents and elite varieties and highlights the critical need to implement genome-informed breeding strategies in future breeding practice.