Project description:Prunus persica (peach) trees carrying the ‘Pillar’ or ‘Broomy’ trait (br) have vertically oriented branches caused by loss of function mutations in a gene called TILLER ANGLE CONTROL 1 (TAC1). TAC1 encodes a protein in the IGT gene family that includes LAZY1 and DEEPER ROOTING 1 (DRO1), which regulat lateral branch and root orientations, respectively. Here, we found that some of the native TAC1 alleles in the hexaploid plum species Prunus domestica, which has a naturally more upright stature, contained a variable length trinucleotide repeat within the same exon 3 region previously found to be disrupted in pillar peach trees. RNAi silencing of TAC1 in plum resulted in trees with severely vertical branch orientations similar to those in pillar peaches but with an even narrower profile. In contrast, PpeTAC1 over-expression in plum led to trees with wider branch angles and more horizontal branch orientations. Pillar peach trees and transgenic plum lines exhibited pleiotropic phenotypes including differences in trunk and branch diameter, stem growth, and twisting branch phenotypes. Expression profiling of pillar peach trees revealed differential expression of numerous genes associated with biotic and abiotic stress, hormone responses, plastids, reactive oxygen, and secondary and cell wall metabolism. Collectively, the data provide important clues for understanding TAC1 function and show that alteration of TAC1 expression may have broad applicability to agricultural and ornamental tree industries.
Project description:In this study, we used vascular specific promoters and a translating ribosome affinity purification strategy to identify phloem associated translatomes in Prunus domestica L. Three different promoter:FLAG-RPL18 lines were used. These included two phloem specific promoters (pSUC2 and pSULTR2;2), as well as the more ubiquitously expressed cauliflower mosaic virus 35S promoter (p35S). Immunopurification of ribosome-mRNA complexes was accomplished by the method described in Reynoso et al. (Plant Functional Genomics: Methods and Protocols, 185-207; 2015). The dataset includes samples from plum leaves taken at 2, 4 and 6 weeks post vernalization.