Industrial hemp (Cannabis sativa L.) is a photoperiod-sensitive short-day crop, yet the quantitative trait loci (QTLs) governing flowering time remain poorly characterized, limiting molecular breeding efforts. To identify genomic regions controlling photoperiodic flowering, we performed bulked segregant analysis sequencing (BSA-seq) coupled with fine linkage mapping using an F2 population derived from a cross between day-neutral (Bubble Kush) and short-day (Aquawoman) accessions. Based on extreme flowering phenotypes, we pooled DNA from 50 early- and 50 late-flowering individuals. A major QTL, qHFX, was mapped to a 2.2 Mb region on chromosome X via ΔSNP-index and Euclidean distance algorithms. Using 15 Kompetitive allele-specific PCR (KASP) markers developed from parental polymorphisms, we refined qHFX to a 637-kb interval in 300 F2 individuals. RNA-seq analysis of Aquawoman under short-day and long-day conditions identified five differentially expressed genes within this interval, with expression profiles validated by quantitative real-time PCR. Sequence analysis revealed a 1-bp indel in LOC115716363, which is homologous to Arabidopsis AHL20/22 and emerged as a strong candidate gene. Notably, heterologous overexpression of LOC115716363 in rice significantly delayed flowering, further supporting its role in flowering time regulation. Collectively, these findings elucidate the molecular basis of flowering time in industrial hemp and provide valuable genomic resources for breeding broadly adapted, high-yield varieties.
Lili Tang, Chao Fan, Lie Yang et al.· Scientific Reports· 0 citations
Introduction Aspartate kinase (AK) functions as a key regulatory enzyme in seed development and amino acid metabolism in plants. Although soybean (Glycine max) is a model high protein crop rich in essential amino acids, systematic characterization of its AK gene family remains limited. Methods To identify AK family genes at the genome wide level and analyze their functions, we performed a comprehensive bioinformatic analysis of the soybean genome, including phylogenetic reconstruction, promoter cis element prediction, transcriptomic profiling, and subcellular localization via GFP fusion assays. Functional validation was conducted using GmAK6 overexpressing transgenic soybean lines, with amino acid profiles quantified by HPLC. Results A total of 16 GmAK genes were identified, unevenly distributed across 10 chromosomes, with segmental duplication as the primary evolutionary driver of family expansion. Promoter analysis revealed that nearly half of the cis acting elements are associated with phytohormone signaling (e.g., jasmonic acid, abscisic acid) and abiotic stress responses (e.g., wounding, low temperature). Transcriptomic data showed distinct spatiotemporal expression patterns, with GmAK5 and GmAK6 significantly upregulated during seed development. GmAK6 was localized to chloroplasts. Amino acid profiling of GmAK6 overexpressing seeds demonstrated increased accumulation of methionine, threonine, and cysteine, alongside reduced levels of glutamate and proline. Discussion These results suggest that GmAK6 plays a regulatory role in amino acid metabolism during seed development and highlight the functional importance of AK genes in soybean.
Chao Fan, Wenwei Liang, Wei Li et al.· Frontiers in Plant Science· 0 citations
