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Abstract Sulfate-proton co-transporters (SULTRs) mediate sulfate uptake, transport, storage and assimilation in plants. The SULTR family has historically been classified into four groups (SULTR1–SULTR4), with well-characterized roles for SULTR groups 1, 2 and 4. However, the functions of the large and diverse SULTR3 group remain poorly understood. Here, we present an updated phylogenetic analysis of SULTRs across angiosperms, including multiple early-divergent lineages. Our results suggest that the enigmatic SULTR3 group comprises four distinct subfamilies that predate the emergence of angiosperms, providing a basis for reclassifying the SULTR family into seven subfamilies. This expanded classification is supported by subfamily-specific gene structures and amino acid substitutions in the substrate-binding pocket. Structural modeling identified three serine residues uniquely lining the substrate-binding pocket of SULTR3.4, enabling three hydrogen bonds with the phosphate ion. The data support the proposed neofunctionalization of this subfamily for phosphate allocation within vascular tissues. Transcriptome analysis of Populus tremula × Populus alba revealed divergent tissue expression preferences among SULTR subfamilies and between genome duplicates. We observed partitioned expression in vascular tissues among the four SULTR3 subfamilies, with PtaSULTR3.4a and PtaSULTR3.2a preferentially expressed in primary and secondary xylem, respectively. Gene coexpression analysis revealed coordinated expression of PtaSULTR3.4a with genes involved in phosphate starvation responses and nutrient transport, consistent with a potential role in phosphate homeostasis. In contrast, PtaSULTR3.2a was strongly coexpressed with lignification and one-carbon metabolism genes and their upstream transcription regulators. PtaSULTR3.2a belongs to a eudicot-specific branch of the SULTR3.1 subfamily found only in perennial species, suggesting a specialized role in lignifying tissues. Together, our findings provide a refined phylogenetic framework for the SULTR family and suggest that the expanded SULTR3 subfamilies have undergone neofunctionalization during the evolution of vascular and perennial plants. 

The direct impact of the COVID-19 pandemic and the indirect impact of the ensuing economic and political response have affected the United States on a large scale. We document a substantial surge in anxiety and depression symptoms from 2019 to 2020 driven by the young adult population, indicating a disproportional indirect impact on the young. Multivariate regression analysis was utilized to quantify the stringency of state responses’ indirect effect on the changes in anxiety or depression symptoms during the pandemic. While we observe a slight decline in the share of the adult population experiencing anxiety and depression through July 2021- June 2022, such decline does not compensate for the large surge of mental health issues among young adults in 2020. Overall, our results indicate that the effects of the stringency of the mitigation measures on different areas of health are complex and vary by state, with a wide variation of mental health-related issues by age group and a higher prevalence in younger adult age categories. After discussing inequities in the accessibility of mental health treatment, lack of health insurance, and implications for quality of life among young adults, this paper adds to the breadth of ongoing COVID-19 research and emphasizes the importance of considering the overall health of the population in a large-scale health crisis as well as discussing the potential unintended consequences of the mitigation measures put in place.