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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #405548
Research Project: Superior Fruit Tree Cultivars for Orchard Resilience, Sustainability, and Consumer Appeal

Location: Innovative Fruit Production, Improvement, and Protection

Title: Phylogenetic and functional analysis of tiller angle control homeologs in allotetraploid cotton

Author
item KANGBEN, FOSTER - Clemson University
item KUMAR, SONIKA - Clemson University
item LI, ZHIGANG - Clemson University
item SREEDASYAM, AVINASH - Hudsonalpha Institute For Biotechnology
item Dardick, Christopher - Chris
item JONES, DON - Cotton, Inc
item SASKI, CHRISTOPHER - Clemson University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2023
Publication Date: 1/31/2024
Citation: Kangben, F., Kumar, S., Li, Z., Sreedasyam, A., Dardick, C.D., Jones, D., Saski, C. 2024. Phylogenetic and functional analysis of tiller angle control homeologs in allotetraploid cotton. Frontiers in Plant Science. 14:1320638. https://doi.org/10.3389/fpls.2023.1320638.
DOI: https://doi.org/10.3389/fpls.2023.1320638

Interpretive Summary: To keep up with the growing global demand for food and fiber, it will be necessary to increase farming productivity. For cotton, productivity is limited by the plant architecture, as the branches tend to grow outward thus requiring more distance between plants. Cotton plants with an upward or vertical orientation have the potential to enable higher planting densities and increase cotton fiber yields per acre. Here we used gene editing to engineer cotton plants with a columnar growth habit where the branches grow vertically instead of horizontally. Achieving this required the mutation of two copies of a gene called TAC1 that is known to suppress the plants response to gravity. TAC1 mutant cotton plants had growth habits there were more compatible for closer plant spacing and thus higher planting densities. This work sets the stage for a new generation of cotton varieties that will substantially increase productivity and allow more cotton to be produced using less land space.

Technical Abstract: Plants have a remarkable ability to adjust their growth to optimize light capture in competitive environments. Branch angle is a critical aspect of plant architecture that influences plant phenotype and physiology. In cereal crops, increased branch angles have been shown to enable improved productivity in high density plantings. The Tiller Angle Control (TAC1) gene, initially discovered as a regulator of tiller inclination in rice and corn, has been found to control branch angle in eudicots. Consequently, manipulation of TAC1 in field crops such as cotton offers potential to improve crop productivity. While most plant species possess a single copy of TAC1, we identified gene duplication events of TAC1 specific to the Gossypium lineage, with 3 copies present in the diploid progenitor species and up to 6 copies in allotetraploid cottons. Sequence analysis of the 6 TAC1 homeologs in Gossypium hirsutum (Coker 312) revealed that these gene copies have diverged from the single copy found in peach, suggesting possible neo- or sub-functionalization. Consistent with this, TAC1 homeologs displayed distinct gene expression patterns in various tissues over developmental time. Significantly elevated expression levels of A11G109300 and D11G112200 were specifically observed in the flower and stem, respectively. The loss of the A11/D11 TAC1 homeologous gene pair created via CRISPR led to a 3-fold reduction in branch angle with altered petiole angles, confirming a role in predominantly controlling branch and petiole angle. These findings present a promising strategy for improving commercial cotton varieties by genetically engineering branch and petiole angles, potentially leading to increased productivity.