Biology

The diversity of floral traits in angiosperms has evolved over time as an adaptive response to reproductive demands. Investigating floral characteristics and pollination systems helps elucidate the evolutionary drivers behind morphological variation in flowers. In this study, we examined A. erythrocarpa to systematically document its floral morphology, stigma receptivity, pollen–ovule ratio, breeding system, and pollinator behavior. Results showed that the sepals abscised completely at the early flowering stage, while stigmas became receptive even during the bud phase. The pollen–ovule ratio was 1773.58 ± 689.75, indicating a facultatively xenogamous breeding system. Bagging experiments further confirmed that the species is self-compatible but does not exhibit apomixis or wind pollination. Field observations identified Agromyzidae sp. and E. balteatus as the primary pollinators, which visited flowers at high frequency after sepal abscission but before anther dehiscence. Compared with its congener A. asiatica, which exhibits delayed sepal abscission and relies mainly on selfing, A. erythrocarpa demonstrates distinct floral morphological adaptations linked to its specialized pollination strategy. These two species thus represent divergent reproductive adaptation patterns within the genus. Therefore, the visiting behavior of fly insects and the early shedding of sepals promotes cross-pollination of A. erythrocarpa.

Cyclic nucleotide-gated channel (CNGC) genes play key regulatory roles in plant immunity and abiotic stress responses. In this study, we conducted a genome-wide identification and analysis of the CNGC gene family in Suaeda glauca. A total of 44 SgCNGC genes were identified. Through phylogenetic analysis, gene structure analysis, chromosome distribution, conserved motif analysis, collinearity analysis, cis-acting element analysis, subcellular localization, and gene overexpression analysis, we systematically characterized the evolutionary relationships, structural features, and potential functions of this gene family. The results indicate that the SgCNGC gene family is evolutionarily highly conserved but exhibits functional divergence in structure and expression. Furthermore, functional assays revealed that overexpression of SgCNGC13 in Arabidopsis thaliana led to increased salt sensitivity, indicating a negative regulatory role for this gene under salt stress. These findings provide a foundation for understanding the role of the CNGC gene family in the growth, development, and stress response of S. glauca and contribute to the remediation of saline–alkali land.

Spermatogenesis is a metabolically intensive process that is highly sensitive to perturbations in proteostasis. The integrated stress response (ISR) and its central effector, ATF4, orchestrate adaptive responses to maintain cellular homeostasis under stress; however, the functional significance of ATF4 in mammalian spermatogenesis has not been established. To investigate this, we engineered a conditional knockout mouse model with germ cell-specific deletion of the Atf4 gene. Results showed that Atf4 deletion did not impair spermatogenesis or male fertility, with knockout mice exhibiting normal testicular histology and standard sperm parameters. Proteomic analysis, however, revealed that ATF4 contributes to testicular protein expression homeostasis, as its deficiency caused marked dysregulation of the testicular proteome, especially impacting SQSTM1/p62 downregulate through endoplasmic reticulum (ER) stress pathway. We conclude that ATF4’s role in regulating proteostatic balance is functionally decoupled from its necessity for the core progression of spermatogenesis. These findings define ATF4 as a potential resilience agent safeguarding testicular function under ER stress, rather than a direct regulator of male germ cell development.