Growth Conditions
Clones of Bignonia magnifica were obtained from cuttings of a single plant cultivated at the gardens of the Biosciences Institute of the University of São Paulo, Brazil (23.56o S, 46.73o W). The average annual temperature in the region is 21.5oC and the mean total annual precipitation is approximately 1600 mm (Brazil National Weather Institute – www.inmet.gov.br).
Sixteen one-year-old plants, each measuring one meter in height, were transplanted to pots measuring 60 cm in diameter and 50 cm in height with soil rich in organic matter in April 2016 (Fig. 2a). Six of these plants were grown with physical supports (stainless-steel wire meshes, 2.1 mm diameter wire, 7x7 cm mesh, Fig. 2b) for two years: five plants were used for self-supporting and lianescent secondary xylem anatomy analysis, and one plant was selected for the collection of cambium and differentiating xylem samples for transcriptome assembling and differential gene expression analysis. The remaining ten plants had their lateral branches and main stem apices pruned to stimulate the production of new branches of the same age (Fig. 2c). These ten plants were divided into two groups for the analysis of physical support impact on the lianescent xylem formation: one group was grown with physical supports (Fig. 2d), and the other group was grown without support aid (Fig. 2e). Pots were spaced 1.5 m apart and were watered to a maximum field capacity three times a week for the first year and weekly thereafter.