Branching is regulated by environmental signals including phytochrome B (phyB)-mediated responses to the ratio of red to far red light. While the mechanisms associated with phytochrome regulation of branching are beginning to be elucidated, there is little information regarding other light signals, including photosynthetic photon flux density (PPFD) and how it influences phytochrome-mediated responses. This study shows that Arabidopsis (Arabidopsis thaliana) branching is modified by both varying PPFD and phyB status and that significant interactions occur between these variables. While phyB deficiency decreased branching when the PPFD was low, the effect was suppressed by high PPFD and some branching aspects were actually promoted. Photosynthesis measurements showed that PPFD may influence branching in phyB-deficient plants at least partially through a specific signalling pathway rather than directly through energy effects on the shoot. The expression of various genes in unelongated buds of phyB-deficient and phyB-sufficient plants grown under high and low PPFD demonstrated potential roles for several hormones, including auxin, cytokinins and ABA, and also showed imperfect correlation between expression of the branching regulators BRC1 and BRC2 and bud fate. These results may implicate additional undiscovered bud autonomous mechanisms and/or components contributing to bud outgrowth regulation by environmental signals.

The northern bobwhite (Colinus virginianus) is an ecologically and economically important avian species. At the present time, little is known about the microbial communities associated with these birds. As the first step to create a quail microbiology knowledge base, the current study conducted an inventory of cultivable quail tracheal, crop, cecal, and cloacal microbiota and associated antimicrobial resistance using a combined bacteriology and DNA sequencing approach. A total of 414 morphologically unique bacterial colonies were selected from nonselective aerobic and anaerobic cultures, as well as selective and enrichment cultures. Analysis of the first 500-bp 16S rRNA gene sequences in conjunction with biochemical identifications revealed 190 non-redundant species-level taxonomic units, representing 160 known bacterial species and 30 novel species. The bacterial species were classified into 4 phyla, 14 orders, 37 families, and 59 or more genera. Firmicutes was the most commonly encountered phylum (57%) followed by Actinobacteria (24%), Proteobacteria (17%) and Bacteroidetes (0.02%). Extensive diversity in the species composition of quail microbiota was observed among individual birds and anatomical locations. Quail microbiota harbored several opportunistic pathogens, such as E. coli and Ps. aeruginosa, as well as human commensal organisms, including Neisseria species. Phenotypic characterization of selected bacterial species demonstrated a high prevalence of resistance to the following classes of antimicrobials: phenicol, macrolide, lincosamide, quinolone, and sulphate. Data from the current investigation warrant further investigation on the source, transmission, pathology, and control of antimicrobial resistance in wild quail populations.

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Biochemical and molecular studies were performed on five unknown bacterial strains isolated from the intestinal contents of Northern Bobwhites (Colinus virginianus) collected from western Texas, USA. The strains were Gram-stain-positive, catalase-negative, non-spore-forming rods arranged in single cells, pairs or short chains. Colonies on Columbia blood agar are circular, flat, entire, approximately 0.5-1.5 mm in diameter and surrounded with a zone of alpha-haemolysis at after incubation for 48 h at 37 °C. Colonies on MRS agar are umbonate with irregular edge, opaque and approximately 1-1.5 mm in diameter after incubation for 48 h. The 16S rRNA gene sequences of the isolates were identical and the highest sequence similarity (97 %) was found to the type strains of Lactobacillus gasseri, L. johnsonii and L. taiwanensis. The strains were distinguishable from related species of the genus Lactobacilluson the basis of carbohydrate fermentation, enzymatic production and fatty acid profiles. The peptidoglycan type is l-Lys-d-Asp (A4α). The DNA G+C content is 35.6 mol%. Major cellular fatty acids are C14 : 0, C16 : 0 and C18 : 1 ω9c. Based on phenotypic, phylogenetic and chemotaxonomic information, the strains represent a novel species of the genus Lactobacillus for which the name Lactobacillus colini sp. nov. is proposed. The type strain is 111144 L1T (=DSM 101872T=KCTC 21086T).