Balsa wood, the lightest commercial timber globally, is a crucial material for producing lightweight composites, especially in wind turbine blades. Expanding its cultivation region is considered essential for advancing renewable energy infrastructure.

Balsa trees (Ochroma lagopus) grown in Xishuangbanna, China, often develop early flowering and branching, leading to non-ideal architecture and significantly lower the wood production.

In a study published in Physiologia Plantarum, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences revealed the molecular mechanism behind early branching in balsa trees, and identified FLOWERING LOCUS T (OlFT-like) as a key regulator of flowering and branching.

Researchers compared an early-branching Indonesian variety with a late-branching cultivar from Ecuador. High-throughput transcriptome sequencing was used to analyze gene expression patterns in the shoot tips of both cultivars.

Genetic analysis showed that the reduced expression of genes responsible for maintaining shoot apical meristem activity was correlated with the loss of apical dominance and increased branching in the Indonesian variety. In contrast, there was a marked upregulation in the expression of flowering-promoting genes in the Ecuador cultivar.

Furthermore, by putting the OlFT-like gene in a model woody plant, Jatropha curcas, researchers observed that the ectopic expression of OlFT-like suppressed main stem vertical growth, promoted branching, and downregulated genes that control meristem activity.

"Our study offers valuable insights into the early screening of superior balsa ecotypes and molecular breeding programs aimed at developing improved varieties with ideal architecture for higher wood yield," said TANG Mingyong from XTBG.