Abstract
Background: Cassava is one of the three major potato crops in the world, and also the sixth-largest food crop in the world. Improving yield is still one of the main goals of cassava breeding. Plant height has a significant impact on the yield and quality of crops. However, the mechanism of cassava plant height development is still unclear.
Results: In this study, we performed phenotypic, anatomic structural, and transcriptomic analyses to study the mechanisms responsible for Cassava plant-height development. Phenotypic and anatomical observations showed that compared to the high-stem cassava cultivar, the dwarf-stem cassava cultivar displayed a significant decrease in plant height, while the internode tissue xylem area significantly increased. Physiological analysis showed that the lignin content of dwarf cassava was significantly higher than that of high cassava. Transcriptome analysis showed that genes involved in cell wall synthesis and expansion, plant hormone signal transduction, phenylpropanoid biosynthesis, and flavonoid biosynthesis were significantly differentially expressed in the internode tissues of two cassava cultivars.
Conclusion: These results indicate that the internode tissue cell division, secondary wall lignification, and hormones and their related gene expressions play an important role in cassava plant height development. It provides new insights into the mechanism of plant height morphogenesis in cassava. In addition, these candidate genes that regulate plant height development can serve as valuable genetic resources for future crop dwarfing breeding.