MdBRC1 and MdFT2 Interaction Fine-Tunes Bud Break Regulation in Apple
Authors: Gioppato, H. A., Estevan, J., Al Bolbol, M., Soriano, A., Garighan, J., Jeong, K., Georget, C., Soto, D. G., El Khoury, S., Falavigna, V. d. S., George, S., Perales, M., Andres, F.
The study identifies the transcription factor MdBRC1 as a key inhibitor of bud growth during the ecodormancy phase in apple (Malus domestica), directly regulating dormancy‑associated genes and interacting with the flowering promoter MdFT2 to modulate bud break. Comparative transcriptomic analysis and gain‑of‑function experiments in poplar demonstrate that MdFT2 physically binds MdBRC1, attenuating its repressive activity and acting as a molecular switch for the transition to active growth.
The study introduced full-length SOC1 genes from maize and soybean, and a partial SOC1 gene from blueberry, into tomato plants under constitutive promoters. While VcSOC1K and ZmSOC1 accelerated flowering, all three transgenes increased fruit number per plant mainly by promoting branching, and transcriptomic profiling revealed alterations in flowering, growth, and stress‑response pathways.
The study measured how plant mass relates to growth rate across 195 European winter wheat cultivars under greenhouse conditions, revealing genetic variation in allometric scaling linked to leaf allocation and development speed. A genetic association with the Photoperiod response-1 (Ppd-1) gene connected greenhouse allometry to genotype‑by‑environment interactions affecting grain yield in field trials, highlighting the agronomic relevance of growth allometry.
The study examined over six decades of USDA Hard Red Spring Wheat Uniform Regional Nursery data to quantify genetic gains in key agronomic traits. It found a modest positive genetic gain of 0.61% per year for grain yield, with stable grain protein levels despite a negative yield‑protein correlation, and highlighted varying gains among breeding programs, especially a ~1% per annum increase in Minnesota's public program.