Minghui Zhao

Peptide deformylase (PDF) belongs to a conserved enzyme family critical for N-terminal methionine excision (NME), an essential protein maturation process in prokaryotes and eukaryotic organelles (chloroplasts, mitochondria). To explore the potential functions of OsPDFs in Oryza sativa, this study employed bioinformatics approaches and experimental validation to systematically identify and analyze the OsPDF gene family. Three OsPDF genes (OsPDF1A, OsPDF1B, OsPDF1B2) were identified in rice. These genes are exclusively distributed on chromosome 1. The biophysical properties of these proteins showed that OsPDF1A and OsPDF1B are alkaline proteins, while OsPDF1B2 is acidic, and all are hydrophilic with moderate thermostability potential. Synteny analysis revealed closer evolutionary relationships between Oryza sativa and the monocot Triticum aestivum than with dicots, reflecting conserved PDF function in gramineous plants. Analysis of cis-acting elements in the 2000 bp upstream region of OsPDF gene promoters revealed numerous elements associated with abiotic stress response and hormone regulation. Furthermore, quantitative real-time PCR (qRT-PCR) data supported these findings, indicating that OsPDF1A and OsPDF1B were upregulated under low-temperature stress, and all three OsPDF genes were transcriptionally activated by heat, salt and UV-B stresses, indicating their active involvement in rice growth, development, and abiotic stress tolerance. In summary, OsPDFs exhibit significant functions in rice’s stress adaptation, growth, and development. This study not only enhances our understanding of the OsPDF gene family’s genomic, evolutionary, and functional characteristics, but also provides new perspectives and foundational data for further exploring their regulatory mechanisms in protein maturation and abiotic stress responses, as well as their potential applications in rice stress tolerance breeding.

Cold stress severely limits rice growth and yield. To overcome the limitations of traditional QTL mapping, this study employed an integrated Meta-QTL and R

Cold stress (CS) significantly impacts rice (Oryza sativa L.) growth during seedling and heading stages. Based on two-year field observations, this study identified two rice lines, L9 (cold stress-sensitive) and LD18 (cold stress-tolerant), showing contrasting CS responses. L9 exhibited a 38% reduction in photosynthetic efficiency, whereas LD18 remained unchanged, correlating with seed rates. Transcriptome analysis identified differentially expressed genes (DEGs) with LD18 showing enriched pathways (carbon fixation, starch/sucrose metabolism, and glutathione metabolism). LD18 displayed dramatically enhanced expression of MAPK-related genes (LOC4342017, LOC9267741, and LOC4342267) and increased ABA signaling genes (LOC4333690, LOC4345611, and LOC4335640) compared with L9 exposed to CS. Results from qPCR confirmed the enhanced expression of the three MAPK-related genes in LD18 with a dramatic reduction in L9 under CS relative to that under CK. We also observed up to 66% reduction in expression levels of the three genes related to the ABA signaling pathway in L9 relative to LD18 under CS. Consistent with the results of photosynthetic efficiency, metabolic analysis suggests pyruvate metabolism, TCA cycle, and carbon metabolism enrichment in LD18 under CS. The study reveals reprogramming of the carbon assimilation metabolic pathways, emphasizing the critical roles of the key DEGs involved in ABA and MAPK signaling pathways in positive regulation of LD18 response to CS, offering the foundation toward cold tolerance breeding through targeted gene editing.

In acidic soils, aluminum (Al) toxicity inhibits the growth and development of plant roots and affects nutrient and water absorption, leading to reduced yield and quality. Therefore, it is crucial to investigate and identify candidate genes for Al tolerance and elucidate their physiological and molecular mechanisms under Al stress. In this study, we identified a new gene OsAlR3 regulating Al tolerance, and analyzed its mechanism from physiological, transcriptional and metabolic levels. Compared with the WT, malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content were significantly increased, superoxide dismutase (SOD) activity and citric acid (CA) content were significantly decreased in the osalr3 mutant lines when exposed to Al stress. Under Al stress, the osalr3 exhibited decreased expression of antioxidant-related genes and lower organic acid content compared with WT. Integrated transcriptome and metabolome analysis showed the phenylpropanoid biosynthetic pathway plays an important role in OsAlR3-mediated Al tolerance. Exogenous CA and oxalic acid (OA) could increase total root length and enhance the antioxidant capacity in the mutant lines under Al stress. Conclusively, we found a new gene OsAlR3 that positively regulates Al tolerance by promoting the chelation of Al ions through the secretion of organic acids, and increasing the expression of antioxidant genes.

The cone is a crucial component of the whole life cycle of gymnosperm and an organ for sexual reproduction of gymnosperms. In Pinus koraiensis, the quantity and development process of male and female cones directly influence seed production, which in turn influences the tree’s economic value. There are, however, due to the lack of genetic information and genomic data, the morphological development and molecular mechanism of female and male cones of P. koraiensis have not been analyzed. Long-term phenological observations were used in this study to document the main process of the growth of both male and female cones. Transcriptome sequencing and endogenous hormone levels at three critical developmental stages were then analyzed to identify the regulatory networks that control these stages of cones development. The most significant plant hormones influencing male and female cones growth were discovered to be gibberellin and brassinosteroids, according to measurements of endogenous hormone content. Additionally, transcriptome sequencing allowed the identification of 71,097 and 31,195 DEGs in male and female cones. The synthesis and control of plant hormones during cones growth were discovered via enrichment analysis of key enrichment pathways. FT and other flowering-related genes were discovered in the coexpression network of flower growth development, which contributed to the growth development of male and female cones of P. koraiensis. The findings of this work offer a cutting-edge foundation for understanding reproductive biology and the molecular mechanisms that control the growth development of male and female cones in P. koraiensis.

Rice (Oryza sativa L.) is a cold-sensitive species that often faces cold stress, which adversely affects yield productivity and quality. However, the genetic basis for low-temperature adaptation in rice remains unclear. Here, we demonstrate that two functional polymorphisms in Oryza sativa SEC13 Homolog 1 (OsSEH1), encoding a WD40-repeat nucleoporin, between the two subspecies Oryza sativa japonica and Oryza sativa indica rice may have facilitated cold adaptation in japonica rice. We show that OsSEH1 of the japonica variety expressed in OsSEH1^MSD plants (transgenic line overexpressing the OsSEH1 allele from Mangshuidao [MSD], cold-tolerant landrace) has a higher affinity for metallothionein 2b (OsMT2b) than that of OsSEH1 of indica. This high affinity of OsSEH1^MSD for OsMT2b results in inhibition of OsMT2b degradation, with decreased accumulation of reactive oxygen species and increased cold tolerance. Transcriptome analysis indicates that OsSEH1 positively regulates the expression of the genes encoding dehydration-responsive element-binding transcription factors, i.e., OsDREB1 genes, and induces the expression of multiple cold-regulated genes to enhance cold tolerance. Our findings highlight a breeding resource for improving cold tolerance in rice.

In this paper, we propose a trajectory planning algorithm for autonomous mine inspection using unmanned aerial vehicles (UAV). Mine inspection presents a set of serious challenges such as narrow roadways and sharp corners. To overcome the disadvantages, the safe flight corridors are calculated to guarantee the safety of the UAV and a multi-objective function is used for optimization to enable the comprehensive performance of the trajectory. A manual inspection with a laser is taken as the input to generate the initial path and point cloud map of the mine environment using the Simultaneous Localization and Mapping (SLAM) algorithm. The initial path can be transformed into a set of waypoints after b-spline smoothing and discrete sampling. The safe flight corridors composed of convex polyhedrons are built based on the waypoints. A multi-objective optimization strategy considering smoothness and time cost is used to generate the piecewise polynomial inspection trajectory and safety is ensured by limiting the trajectory inside the safe flight corridors. Experimental results demonstrate that the proposed approach can perform well in autonomous mine inspection.