Appropriate mowing can promote the growth of Anabasis aphylla through the auxin metabolism pathway.

Anabasis aphylla (A. aphylla), a species of the Amaranthaceae family, is widely distributed in northwestern China and has high pharmacological value and ecological functions. However, the growth characteristics are poorly understood, impeding its industrial development for biopesticide development. Here, we explored the regenerative capacity of A. aphylla. To this end, different lengths of the secondary branches of perennial branches were mowed at the end of March before sprouting. The four treatments were no mowing (M0) and mowing 1/3, 2/3, and the entire length of the secondary branches of perennial branches (M1-M3, respectively). Next, to evaluate the compensatory growth after mowing, new assimilate branches' related traits were recorded every 30 days, and the final biomass was recorded. The mowed plants showed a greater growth rate of assimilation branches than un-mowed plants. Additionally, with the increasing mowing degree, the growth rate and the final biomass of assimilation branches showed a decreasing trend, with the greatest growth rate and final biomass in response to M1. To evaluate the mechanism of the compensatory growth after mowing, a combination of dynamic (0, 1, 5, and 8 days after mowing) plant hormone-targeted metabolomics and transcriptomics was performed for the M0 and M1 treatment. Overall, 26 plant hormone metabolites were detected, 6 of which significantly increased after mowing compared with control: Indole-3-acetyl-L-valine methyl ester, Indole-3-carboxylic acid, Indole-3-carboxaldehyde, Gibberellin A24, Gibberellin A4, and cis (+)-12-oxo-phytodienoic acid. Additionally, 2,402 differentially expressed genes were detected between the mowed plants and controls. By combining clustering analysis based on expression trends after mowing and gene ontology analysis of each cluster, 18 genes related to auxin metabolism were identified, 6 of which were significantly related to auxin synthesis. Our findings suggest that appropriate mowing can promote A. aphylla growth, regulated by the auxin metabolic pathway, and lays the foundation for the development of the industrial value of A. aphylla.

Genome-wide association study and transcriptome analysis reveal key genes controlling fruit branch angle in cotton.

Fruit branch angle (FBA), a pivotal component of cotton plant architecture, is vital for field and mechanical harvesting. However, the molecular mechanism of FBA formation is poorly understood in cotton. To uncover the genetic basis for FBA formation in cotton, we performed a genome-wide association study (GWAS) of 163 cotton accessions with re-sequencing data. A total of 55 SNPs and 18 candidate genes were significantly associated with FBA trait. By combining GWAS and transcriptome analysis, four genes underlying FBA were identified. An FBA-associated candidate gene Ghi_A09G08736, which is homologous to SAUR46 in Arabidopsis thaliana, was detected in our study. In addition, transcriptomic evidence was provided to show that gravity and light were implicated in the FBA formation. This study provides new insights into the genetic architecture of FBA that informs architecture breeding in cotton.

Genetic Mapping and Analysis of a Compact Plant Architecture and Precocious Mutant in Upland Cotton.

With the promotion and popularization of machine cotton-picking, more and more attention has been paid to the selection of early-maturity varieties with compact plant architecture. The type of fruit branch is one of the most important factors affecting plant architecture and early maturity of cotton. Heredity analysis of the cotton fruit branch is beneficial to the breeding of machine-picked cotton. Phenotype analysis showed that the types of fruit branches in cotton are controlled by a single recessive gene. Using an F2 population crossed with Huaxin102 (normal branch) and 04N-11 (nulliplex branch), BSA (Bulked Segregant Analysis) resequencing analysis and GhNB gene cloning in 04N-11, and allelic testing, showed that fruit branch type was controlled by the GhNB gene, located on chromosome D07. Ghnb5, a new recessive genotype of GhNB, was found in 04N-11. Through candidate gene association analysis, SNP 20_15811516_SNV was found to be associated with plant architecture and early maturity in the Xinjiang natural population. The GhNB gene, which is related to early maturity and the plant architecture of cotton, is a branch-type gene of cotton. The 20_15811516_SNV marker, obtained from the Xinjiang natural population, was used for the assisted breeding of machine-picked cotton varieties.