BMC Plant Biology最新文献

Background: The regreening stage (RS) is a critical agronomic trait impacting yield potential in rapeseed (Brassica rapa L.), yet its underlying genetic mechanisms remain largely unexplored. Field observations indicate that early-regreening cultivars, like 'Hengyou 8', exhibit a longer grain-filling period and higher thousand-seed weight (TSW) compared to late-regreening cultivars like 'Hengyou 6'. This study aimed to systematically dissect the genetic basis of RS initiation to identify key regulatory genes and provide resources for molecular breeding.

Results: We constructed an F₂ population from a cross between 'Hengyou 8' and 'Hengyou 6' and employed Bulk Segregant Analysis sequencing (BSA-seq), which identified 11 quantitative trait loci (QTLs) associated with RS on chromosomes A01, A02, A04, A05, A06, A08, A09, and A10. Concurrently, transcriptome sequencing (RNA-seq) of shoot apical meristems and roots across the RS process revealed 17,242 differentially expressed genes (DEGs). Integrated analysis of BSA-seq and RNA-seq data pinpointed 15 high-confidence candidate genes within the QTL regions. These include NAC016, NAC017, MYC2, and DDE2, which are primarily involved in jasmonic acid (JA) metabolism, phytohormone signaling, cell development, and stress responses. Expression profiling showed distinct spatiotemporal patterns for these genes between the parental lines, suggesting their roles in modulating the timing of regreening.

Conclusions: Our findings provide the first comprehensive genetic map of the regreening process in rapeseed, revealing a dynamic regulatory network centered on JA signaling and stress response pathways. The identified candidate genes and associated molecular markers establish a valuable resource and a solid theoretical foundation for future functional studies. More importantly, we have identified direct targets for marker-assisted selection (MAS). This provides a foundation for breeding novel rapeseed cultivars with optimized regreening timing and enhanced yield potential.

Drought is one of the major abiotic stress factors limiting the growth, development, and yield of potato (Solanum tuberosum L.). Melatonin, a novel plant hormone, has recently shown significant potential in enhancing plant stress resistance. However, its regulatory mechanisms in response to drought stress in potato remain unclear. In this study, potato seedlings were treated with different concentrations of exogenous melatonin (50, 100, and 150 µmol L⁻¹) under controlled drought conditions to systematically evaluate their physiological and molecular responses. The results demonstrated that appropriate melatonin application, especially at 100 µmol L⁻¹ effectively alleviated drought-induced growth inhibition, oxidative stress, and photosynthetic impairment. This was evidenced by increased plant height, enhanced photosynthetic efficiency, reduced reactive oxygen species (ROS) accumulation, decreased cell death and lipid peroxidation, as well as elevated antioxidant enzyme activities (superoxide dismutase - SOD, catalase - CAT, peroxidase - POD) and levels of osmoprotectants (proline - Pro and soluble sugars - SS). Transcriptome analysis revealed that melatonin modulates numerous drought-responsive differentially expressed genes (DEGs), including multiple transcription factor (TF) families (e.g., MYB, NAC, ERF), and pathways related to photosynthesis, antioxidative metabolism, hormone signaling, and carbon metabolism. Furthermore, weighted gene co-expression network analysis (WGCNA) and Mfuzz clustering identified key gene modules and central hub genes strongly associated with photosynthetic performance and antioxidant indicators. Overexpression of StMYB and StAPX in Arabidopsis significantly enhanced drought tolerance by improving antioxidant enzyme activities and maintaining membrane stability under water-deficit conditions. This study provides a theoretical foundation for applying melatonin in potato drought stress mitigation and lays a molecular basis for developing melatonin-based agronomic strategies for improving drought tolerance.

This study examined the associations between genotypic variation, environmental conditions, and the phytochemical composition, mineral content, and antioxidant capacity of wild Prunus cerasifera genotypes in diverse ecogeographic regions of Eastern Anatolia (Türkiye). Thirteen genotypes were evaluated for morphological, physicochemical, and biochemical traits under varying climatic conditions, including temperature, humidity, precipitation, and solar radiation. Principal Component Analysis (PCA) revealed the multidimensional nature of this variation, indicating that environmental variables, particularly temperature and solar radiation, were associated with differences in mineral accumulation and phenolic compound levels. Warmer and sunnier environments were linked to higher nutritional density, while genotypes from more humid conditions exhibited a "dilution effect," reflecting a balance between fruit size and bioactive compound concentration. Substantial variation was observed among genotypes, with up to a five-fold difference in total phenolic content and marked differences in mineral composition, highlighting the broad genetic diversity in wild populations. Certain genotypes showed notable nutritional characteristics: 44PC01 had the highest flavonoid content and antioxidant capacity, 23PC05 accumulated higher levels of macroelements (Mg, K, Ca), and 44PC03 and 44PC07 contained the highest microelements (Fe, Zn, Cr). Partial correlation analysis, after accounting for genotypic differences, suggested that genetic background was the main source of variation in fruit quality traits, while associations with environmental variables were comparatively weaker. Overall, these findings provide evidence of phenotypic and biochemical diversity among wild P. cerasifera genotypes and emphasize their value as genetic resources for conservation and future multi-year breeding studies.