生命科学最新文献

Kalmia procumbens (K. procumbens), a ubiquitous alpine dwarf shrub, thrives at high elevations, particularly on wind-exposed sites. Plants on contrasting north- and southeast-facing slopes at ~2237 m elevation exhibit differences in leaf colour and growth, suggesting acclimative strategies. Leaves from the southeast-facing slope, exposed to higher leaf temperatures (54°C), stronger winds (21 m ∙ s^-1), and increased solar irradiation (2319 µMol photons m^-2 ∙ s^-1), developed thicker cuticles (16 µm) than leaves from north-facing slope (11 µm). Raman imaging revealed that cutin and triterpenoids built the foundation in all cuticles on the adaxial and abaxial leaf sides sampled from the two contrasting slopes, while flavonoids accumulated mostly in the outer adaxial cuticle layer and reached the highest values at the N-site. The thicker cuticle of the S-site was mainly composed of cutin and triterpenoids, while the flavonoids were restricted to a thinner outer layer. Minimum diffusive conductance (g_min) was lower in the S-site leaves, which may be associated to their thicker cuticle. The water permeability (g_min) increased exponentially with temperature in leaves from both slopes. Under heat, above 38°C, north-facing leaves with higher flavonoid content lost increasingly more water. While the flavonoids will defend bacterial and fungal pathogens and have a vital role in enhancing plant resilience, they seem to promote higher water permeability of the cuticle of K. procumbens. By combining physiological, structural and chemical insights, our findings suggest that micro-environmental factors play a significant role in driving acclimative responses in K. procumbens. Cuticle structure, composition and function are finely tuned to alpine microhabitats and illustrate a distinct potential for phenotypic adjustment to environmental and biotic constraints.

Soft rot is a major disease restricting the production of colored calla lily, with severe impacts on their ornamental, commercial, and market value, caused by infection with Pectobacterium carotovorum. This study investigated the involvement of long noncoding RNAs (lncRNAs) in the soft rot response of colored calla lily leaves. Transcriptome sequencing of infected leaves identified 35,175 potential lncRNAs. Differential expression analysis revealed significant upregulation or downregulation of numerous lncRNAs following infection, indicating their potential involvement in the plant's immune response to P. carotovorum. Among these, LNC86472 was identified as a differentially expressed lncRNA that functions as a potential endogenous target mimic (eTM) for miR166a. Meanwhile, miR166a directly targets homeodomain-leucine zipper 15 (HB15) transcripts, which activates immune responses and restricts pathogen invasion. Functional studies involving the transient expression and silencing of LNC86472 and HB15 in colored calla lily leaves demonstrated that overexpression resulted in enlarged lesion sizes and compromised plant immune responses, while silencing them led to the opposite effect. Notably, infection-induced increases in jasmonic acid levels were associated with the downregulation of LNC86472. Further analysis showed that MYC2 directly binds to the LNC86472 promoter to repress its expression. These results suggest that jasmonic acid (JA)-mediated downregulation of LNC86472 releases miR166a, thereby facilitating miR166a-mediated cleavage of HB15 transcripts. This study provides new insights into the role of lncRNAs in the soft rot infection process of colored calla lily.

Rice blast, caused by the fungus Magnaporthe oryzae, severely impacts rice yield and quality. Plants possess intricate molecular mechanisms to recognize and respond to pathogen infections. In this study, we demonstrated that the infection of M. oryzae induces the expression of prePSK, the precursor of the endogenous small peptide, phytosulfokine, in rice. The exogenous application of active PSKα significantly enhances rice resistance to rice blast. Conversely, the PSK septuple mutant exhibits reduced resistance against M. oryzae, indicating the involvement of PSK in the defense response against rice blast. Through genetic and biochemical evidence, we identified OsPSKR2 as a functional PSK receptor that is essential for PSK-mediated rice blast resistance. Intriguingly, the overexpression of OsPSKR2 promotes the expression of pathogenesis-related (PR) genes and increases reactive oxygen species (ROS) production, thus strengthening rice blast resistance without negatively affecting plant growth or yield. Moreover, we established that the OsPSK-PSKR2 signaling cascade, whose activity depends on OsTPST-mediated PSK tyrosine sulfation, is necessary for immunity against both rice blast and leaf blight. Thus, our study elucidates the role of PSK-PSKR module in broad-spectrum disease resistance in rice.

The cover image is based on the article Chemical Communication Between Plant and Microbe in the Phyllosphere by Xuanxuan Ma et al., https://doi.org/10.1111/pce.70314.

Antarctica's extreme cold challenges terrestrial life. In plants, β-ketoacyl-CoA synthase (KCS) is a critical enzyme for very long-chain fatty acids (VLCFAs) biosynthesis. However, the role of KCS genes in Antarctic mosses-the dominant terrestrial flora in this harsh ecosystem-remains poorly understood. Here, we performed a comparative analysis of cold tolerance and VLCFAs profiles between the Antarctic moss Pohlia nutans and the model bryophyte Physcomitrella patens, combined with functional characterization of the P. nutans KCS gene family (PnKCS1-19). P. nutans demonstrated superior growth rates and cold tolerance compared to P. patens. Furthermore, the PnKCS gene family has undergone substantial expansion via whole genome duplication, with intra-clade sequence homology exceeding 95.0%. Notably, heterologous expression of the PnKCS gene family in both wild-type and mutant yeast systems revealed novel VLCFAs profiles in some yeast strains, reflecting the distinct catalytic capabilities of PnKCSs. Heterologous of PnKCS7 and PnKCS8 in P. patens, which catalyzed the synthesis of a novel VLCFA component (C30:0) in wild yeast, enhanced the cold tolerance and total VLCFAs content of plant. These findings reveal the mechanism of Antarctic P. nutans adaptation via KCS-mediated VLCFAs synthesis, underscoring the ecological role of lipid remodeling.