Translatome and metabolome effects triggered by gibberellins during rosette growth in Arabidopsis

Although gibberellins (GAs) are well known for their growth control function, little is known about their effects on primary metabolism. Here the modulation of gene expression and metabolic adjustment in response to changes in plant (Arabidopsis thaliana) growth imposed on varying the gibberellin regime were evaluated. Polysomal mRNA populations were profiled following treatment of plants with paclobutrazol (PAC), an inhibitor of GA biosynthesis, and gibberellic acid (GA3) to monitor translational regulation of mRNAs globally. Gibberellin levels did not affect levels of carbohydrates in plants treated with PAC and/or GA3. However, the tricarboxylic acid cycle intermediates malate and fumarate, two alternative carbon storage molecules, accumulated upon PAC treatment. Moreover, an increase in nitrate and in the levels of the amino acids was observed in plants grown under a low GA regime. Only minor changes in amino acid levels were detected in plants treated with GA3 alone, or PAC plus GA3. Comparison of the molecular changes at the transcript and metabolite levels demonstrated that a low GA level mainly affects growth by uncoupling growth from carbon availability. These observations, together with the translatome changes, reveal an interaction between energy metabolism and GA-mediated control of growth to coordinate cell wall extension, secondary metabolism, and lipid metabolism

Bacterial Infective Stifle Arthritis Secondary to a Migrating Grass Seed Foreign Body in an Adult Dog

An adult neutered male cocker spaniel was presented with a 2-3week history of left pelvic limb lameness, stifle effusion, general malaise and pyrexia. Computed tomography (CT) imaging revealed an irregular tubular tract, extending from the stifle distally to the level of the mid tibial diaphysis, associated with the long digital extensor muscle. Ultrasonography revealed the tract had echogenic contents, however no foreign body could be identified. Following surgical exploration, a grass seed was identified in the medial compartment of the left stifle. Culture of the grass seed and joint capsule tissue yielded growth of Pantoea agglomerans. Following the surgery and subsequent antibacterial and non-steroidal anti-inflammatory medication, the dog made a full recovery to normal activity