Molecular Plant最新文献

Aroma differentiation is a key trait that distinguishes citrus and other horticultural crops from staple crops. However, the mechanistic basis and sensory features of the distinctive and varied citrus-like aromas of citrus remain poorly understood. In this study, we demonstrated that γ-terpinene determines tangerine-like aroma, affects consumer preference, and has pest-repellent properties. Both forward and reverse genetic analyses uncovered the pivotal role of CreTPS3a in γ-terpinene biosynthesis. In addition, we identified a solo long terminal repeat (solo-LTR) insertion upstream of the CreTPS3a promoter in MD1-type domesticated mandarins. We found that the transcription factor CreARF2 specifically binds to this solo-LTR and positively regulates CreTPS3a expression and γ-terpinene accumulation. Notably, this regulatory mechanism may be associated with the geographic distribution patterns of tangerine germplasms. By integrating sensory evaluation with insect behavioral assays, we identified a γ-terpinene sensory threshold of approximately 50 μg/g, which optimally balances pest-repellent properties with consumer preference. Collectively, these findings reveal the molecular mechanisms that underlie the production of tangerine-like aroma, illustrate the complex interactions among citrus plants, human beings, and insects, and offer new possibilities for the development of innovative, eco-friendly strategies that may simultaneously enhance fruit aroma and strengthen plant defense against pests.

Potato is an important crop for ensuring global food and nutritional security. The metabolic transitions and underlying genetic mechanisms that occurred during potato domestication from wild progenitors remain not fully understood. In this study, we used a multi-omics approach to decipher its domestication footprint. The metabolomic remodeling of potato tubers featured a decrease in diversity and content of bitter steroidal glycoalkaloids (SGAs) and an increase in nutritional flavonoid content. Two biosynthesis genes affecting the structural divergence of SGAs and two transcription factors that regulate SGA content in potato were characterized. Two tandem MYB transcription factors were shown to modulate the phenylpropanoid flux between phenolic acids and flavonoids. Furthermore, we uncovered that selection of coding and cis-regulatory variations has substantially reshaped tuber metabolite diversity and content, respectively. Through dissection of the genetic architecture of 2046 loci for 568 metabolites, we identified 2745 epistatic interactions and 268 pleiotropic effects, providing a roadmap for metabolic manipulation in tubers. Taken together, these findings deepen our understanding of potato domestication and offer genetic strategies for developing cultivars with improved quality.

Rice yield remains limited by trade-offs between effective panicle number, grain number per panicle, and grain weight. However, the molecular mechanisms linking auxin transport to panicle formation in rice remain largely unknown. In this study, we conducted genome-wide association studies and identified Suppressor of Effective Panicle 1 (SEP1), which encodes a basic helix-loop-helix transcription factor that negatively regulates effective panicle number and yield. SEP1 directly activates OsPIN1a and OsPIN1b, two auxin efflux carriers that modulate auxin transport and distribution in tiller buds. Natural variation in SEP1 alters the transcriptional activation capacity of SEP1, and the SEP1^Hap2 allelic variant exhibits weaker transcriptional activation of OsPIN1a and OsPIN1b, correlating with its prevalence in Xian cultivars with relatively higher panicle numbers. Furthermore, we discovered that Gnp4/LAX PANICLE 2, a RING finger and WD40-associated ubiquitin-like domain-containing protein, destabilizes SEP1 via ubiquitin-proteasome degradation, fine-tuning auxin transport and tiller bud elongation. Notably, knockout of SEP1 in Xian/Geng cultivars significantly increases yield in field trials. Collectively, our study reveals a molecular mechanism for regulating rice yield and provides a practical strategy for breeding high-yield rice.