Background: Gossypium hirsutum L. is one of the main economic crops worldwide, and increasing the size/weight of its seeds is a potential strategy to improve its seed-related yield. AINTEGUMENTA (ANT) is an organogenesis transcription factor mediating cell proliferation and expansion in Arabidopsis, but little is known about its candidate function in upland cotton seed. Results: In this study, functional characterization of GhANT in the cotton seed development stage was performed. The expression pattern analysis showed that GhANT was predominantly expressed in the ovules, and its expression was consistent with the ovules’ development stage. Heterologous expression of GhANT in Arabidopsis promoted plant organ growth and led to larger seeds. Importantly, specific expression of GhANT by the TFM7 promoter in the cotton ovules enlarged the seeds and increased the cotton seed yield, as compared with the wild-type in a three-year field trial. Furthermore, transcription level analysis showed that numerous genes involved in cell division were up-regulated in the ovules of TFM7::GhANT lines in comparison to the wild-type. These results indicate that GhANT is a potential genetic resource for improving cotton seed yield through its molecular links with cell cycle controllers.

Soybean (Glycine max (L.) Merr.) was originally domesticated in China and is a kind of significant leguminous crop, which can fix atmospheric nitrogen to bioavailable nitrogen in association with rhizobia. Ceramides, intermediates of sphingolipids, are crucial structural components in membrane formation and also function as signaling molecules, which play crucial roles in plant development and defense. Although Arabidopsis ceramide synthase genes AtLOH1 and AtLOH3 overexpression plants increased biomass compared to the wild type, the potential mechanism in plant growth was still unclear. A soybean ceramide synthase gene 1 (GmCS1) has a high expression level in the stem, and the protein is localized in the endoplasmic reticulum. Overexpression of GmCS1 promotes soybean lateral branch development for effective branch formation, significantly increasing the number of lateral branches and pods. Using transcriptomic profiles, we found that GmCS1 overexpression lines displayed the upregulation of plant hormone signal transduction pathway gene expression in developmental branches. Actually, Indole-3-acetic acid (IAA) induces bud outgrowth rather than initiation according to the determination of endogenous IAA and cytokinin (CKs) in soybean lateral branches. Collectively, these results suggest that GmCS1 may be a functional ceramide synthase gene in soybean, with the GmCS1-mediated regulatory network playing a crucial role in controlling branch development by IAA and CKs homeostasis. Exploring the regulation mechanisms by GmCS1 overexpression lines is essential for Ideal Soybean Architecture (ISA) innovation.