What factors control plant height?1

Plant height (PH) is one of the most important components of a plant ideotype, affecting plant biomass, yields, lodging resistance, and the ability to use mechanized harvesting. As many complex pathways controlling plant growth and development remain poorly understood, we are still unable to obtain the most ideal plants solely through breeding efforts. Plant height can be influenced by genotypes, plant hormone regulations, environmental conditions, and interaction with other plants. Here, we comprehensively review the factors influenced PH, including the regulation of PH-related development processes, the genetics and QTLs contributing to PH, and the hormone-regulated molecular mechanisms for PH. Additionally, the symbiotic influence of grafting on PH was discussed focusing on molecular regulation of gene expressions and genetics. Finally, we proposed strategies on how to apply recent findings to breeding for better PH, highlighted some knowledge gaps, and suggested potential directions for future studies.