Interactions of airborne methyl jasmonate with vegetative storage protein gene and protein accumulation and biomass partitioning in Populus plants

In young poplar (Populus nigra Muench × Populus maximowiczii A. Henry) plants, vegetative storage proteins (VSPs), the bark storage protein (BSP), and (or) woundinducible 4 protein (WIN4) mRNAs were present in the apical and basal leaves and in the basal leaves, respectively. VSPs accumulated in the apical leaves and to a lesser extent in the stem. The response of the plants to 20 µM airborne methyl jasmonate (MJ) was examined in four parts ( apical and basal leaves, stem, and roots) in both short-term (within 72 h) and long-term (1, 2, 3, and 4 weeks) experiments. In the short-term, MJtreated plants either induced or increased the part-specific expression of win4 and bsp, and accumulation of BSP and (or) WIN4. In the long-term, MJ treatment resulted in Apart-specific alterations in protein and nitrogen concentration and further altered BSP and WIN4 accumulation. The MJ-treated plants increased both the biomass allocation to the stem, without a change in the relative growth rate, and the tolerance low temperature (-2°C). Together, these results suggest the BSP and WIN4 are both involved in short-term N cycling and that exogenous MJ treatment promotes changes in nitrogen metabolism in poplar.