Jul 2026· The Plant Journal· Vol 127 1, pp.
e71039
· 0 citations· 50 references
Medicine
TL;DR
The genetic basis of determinate growth is uncovers and insights into the mechanisms of flowering regulation in cotton are provided and have significant implications for breeding strategies to improve cotton plant architecture.
Abstract
Crop flowering, a critical aspect of plant growth, is influenced by genetic and environmental factors. The indeterminate growth of cotton can lead to asynchronous flowering and boll setting. This study identified and characterized a determinate growth mutant, dt2, in Gossypium arboreum (G. arboreum) Shixiya 1 (SXY1) through EMS mutagenesis. The dt2 mutant exhibited main axis termination and shoot apical meristem (SAM) transition into flowers. Map-based cloning revealed a single nucleotide mutation in the coding sequence (CDS) of GaFL (Ga07G0556), a FLORICAULA/LEAFY homolog responsible for the determinate growth phenotype. Virus-induced gene silencing (VIGS) and protein interaction assays, including bimolecular fluorescence complementation, luciferase imaging, and GST pull-down, were employed to functionally characterize GaFL and its Gossypium hirsutum (G. hirsutum) homolog GhFL (Gh_A07G051000). These integrated approaches demonstrated the critical roles of both proteins in cotton development. The results indicated that GhFL interacts with GhSP2 (Gh_D09G150100), both of which negatively influence flowering time in cotton. Furthermore, a reduction of GhSP2 expression resulted in increased GhJAZ5 (Gh_D06G087500) expression while overexpression of GhJAZ5 in cotton promoted early flowering. This research uncovers the genetic basis of determinate growth and provides insights into the mechanisms of flowering regulation in cotton. These findings have significant implications for breeding strategies to improve cotton plant architecture.
Auxin is an important regulator of reproductive development. The families of the AUXIN RESPONSE FACTOR (ARF) genes, important components of the auxin signal, have expanded in flowering plants. Tomato (Solanum lycopersicum) has two copies of ARF8, which are negatively regulated by miR167. Here, we investigated the involvement of this expanded SlmiR167-SlARF8 module in flower development. Mutants were generated in 5 SlmiR167 and 2 SlARF8 genes, and flower development and fruit set were characterized in mutant combinations. We show that the SlmiR167-SlARF8 module regulates flower-organ development and fruit set. The two SlARF8 paralogs are found to have both overlapping and distinct roles. They additively affect stigma position by oppositely affecting stamen and pistil growth, while SlARF8B has evolved a unique role in the inhibition of anther dehiscence. Loss of SlARF8B in the Slmir167a background uncovers a unique reproductive syndrome of fast, early, fertilization-independent fruit set and increased yield under cold stress, mediated by the deregulation of SlARF8A. These results demonstrate how gene duplication within the miR167-ARF8 module enables fine-tuning of auxin signaling to achieve coordinated, robust reproductive development, with implications for the control of fruit set in tomato.
Nave Man, Naama Teboul, Amir Bahu et al.· New Phytologist· 0 citations
Shoot branching is an important trait that influences plant architecture and crop productivity. It is triggered by the perception of developmental and environmental cues and controlled by a complex and interconnected regulatory network. Multiple plant hormones, including strigolactones (SLs), auxin and cytokinin (CK) regulate branching; however, the interplay between them has yet to be fully elucidated. In this study, branching regulators were identified through a series of transcriptomic, functional and genetic studies. Based on gene expression that was correlated with either bud growth suppression or bud outgrowth in petunia from our previous work, candidates for branching regulation were selected, and their functions in modulating branching were studied using Arabidopsis mutant lines. The SCARECROW-LIKE28 mutant (scl28) and CYTOKININ OXIDASE/DEHYDROGENASE double mutant (ckx3 ckx5) showed significant reduction in rosette branching and altered flowering time relative to wild type (WT) Arabidopsis. Transcriptome comparison between these mutants and WT suggested upregulation of SL biosynthesis genes in the mutants might contribute to the suppression of rosette branching. This was supported by genetic data indicating that SCL28 and CKX3/5 regulate rosette branching via the SL signalling pathway but regulate flowering independently. These findings add new knowledge to the regulation and connection between SL and other hormones and developmental processes.
Zhiwei Luo, B. Janssen, Janine Cooney et al.· Journal of Experimental Bota...· 0 citations
It is found that Rht5 reduces plant height through inhibition of cell proliferation while it promotes cell elongation during wheat stem elongation, providing new insights into the molecular mechanism of the Rht5-mediated plant height regulatory pathway and valuable gene resource for the genetic improvement of wheat plant architecture.
Xianglan Kong, Yuxin Lei, Aozhe Wang et al.· Theoretical and Applied Gene...· 0 citations
The pistil, a key female reproductive organ in flowering plants, plays a critical role in sexual reproduction. Although pistil function has been well studied in some species, the molecular mechanisms governing its development in rice (Oryza sativa) remain unclear. Here, we isolated and characterized a female-sterile rice mutant, Osdpms1, that exhibits pleiotropic reproductive defects, including greater stigma number and aberrant gametophyte development, while maintaining normal vegetative growth and male fertility. Using map-based cloning, genetic complementation, and CRISPR-Cas9 knockout experiments, we determined that LOC_Os07g03160 (named OsDPMS1), encoding a protein containing a WD40 repeat domain, is the causal gene underlying the mutant phenotype. OsDPMS1 was predominantly expressed during the flowering stage, and subcellular localization experiments revealed that OsDPMS1 localizes to both the nucleus and the cytoplasm. Using yeast two-hybrid, bimolecular fluorescence complementation, and GST-pulldown assays, we demonstrated that OsDPMS1 physically interacts with three components of the 26S proteasome pathway: OsUBQ, OsCDC48, and OsCDC48E. Furthermore, we showed that the female sterility of Osdpms1 can be efficiently maintained via seed production technology. When we combined Osdpms1 with male-sterile lines for hybrid seed production in a mixed planting manner, we achieved yield potentials comparable to those using conventional row-planting methods. Our findings establish OsDPMS1 as a critical regulator of pistil development and female fertility in rice and highlight its potential application in hybrid rice breeding programs.
In the crop Brassica napus (oilseed rape), distinct growth types have been established that differ mainly in their vernalization requirement for flowering. The need for vernalization in Arabidopsis is controlled by the expression of the floral repressor FLOWERING LOCUS C (FLC), which also regulates cold-responsive flowering in B. napus. Notably, FLC homologs are also retained in spring oilseed rape despite its lack of vernalization requirement. To elucidate the functions of the nine BnFLC homologs in a spring type, we generated CRISPR/Cas9 knockout mutants of all homologs in the cultivar Westar. We show that the loss of BnFLC genes significantly accelerates flowering, demonstrating that BnFLC genes regulate flowering in spring types independently of vernalization. Transcriptomic analyses in leaves revealed distinct expression patterns among the BnFLC genes, with some remaining active during floral transition. Finally, no epigenetic regulation of the BnFLC homologs associated with flowering time was detected, while BnFLC.A03b carried persistent repressive marks and was constitutively silenced. Unexpectedly, additional flowering time regulators, including genes typically active in the shoot apical meristem, were expressed in leaves, with some showing altered expression and chromatin states in the mutant. These findings reveal that BnFLC genes are developmentally regulated and directly control flowering in spring oilseed rape, while also modulating the expression of other floral regulators in B. napus. CRISPR/Cas9 knockout of all nine BnFLC homologs reveals that these genes regulate flowering time developmentally in spring oilseed rape while influencing the expression and chromatin states of downstream flowering regulators.
Sarah Duveneck, Kea Ille, S. Melzer· Plant Molecular Biology· 0 citations
Trichomes are crucial for plant resistance to biotic and abiotic stresses. In cucumber, the density and morphology of fruit spines directly influence fruit appearance and market value, making them a key agronomic trait. Nevertheless, the genetic regulators governing trichome initiation and development remain poorly understood. In this study, the AP2/ERF transcription factor ENHANCER OF SHOOT REGENERATION 1 (CsESR1) was identified and shown to be predominantly expressed in the epidermis of stems, leaves, flower buds, and ovaries, as confirmed by quantitative reverse transcriptase-polymerase chain reaction and GUS staining analyses. CRISPR/Cas9-mediated knockout of CsESR1 resulted in a marked decrease in spine density, altered spine morphology, and a glabrous phenotype in vegetative tissues including stems, leaves, and tendrils. Furthermore, the defective development of bloom trichomes in the Csesr1 mutant resulted in increased glossiness of the fruit peel. Protein interaction assays revealed that CsESR1 physically associates with key trichome regulators, CsTOE3, CsGL1, and CsTRY. Moreover, Csesr1 plants exhibited reduced aphid resistance, concomitant with altered expression of defense-related genes, phytohormone levels, and antioxidant enzyme activities. Collectively, this study establishes CsESR1 as a key regulator of trichome formation in cucumber and uncovers its role in plant defense, providing novel insights into the molecular networks coordinating epidermal differentiation and stress adaptation.
Piaoyun Sun, Jinqiang Yan, Wenrui Liu et al.· The Plant Journal· 0 citations