An investigation studied the impact of various solid waste types on Helianthus plant growth, encompassing both Helianthus annuus and Helianthus giant. Common sunflowers (Helianthus) were cultivated to assess the influence of soil substrates with differing compositions and solid waste concentrations on plant growth and morphology. Materials included fireplace ash, oil burner dust, forge dust, land of Milos (pozzolan), and land of Milos mixed with olive core. The aim was to determine if Helianthus could remediate soil contaminated by these wastes. Results re-vealed plant growth relied on substrate quality and quantity. High concentrations of fireplace ash and oil burner dust were detrimental, while forge dust, land of Milos, and olive core combinations supported satisfactory growth and improved resistance. Generally, Helianthus annuus outper-formed Helianthus giant. These findings highlight Helianthus' potential for soil restoration and decontamination under specific substrate conditions concerning solid waste type and concentration.

Mutations that provide environment dependent selective advantages drive adaptive divergence among species. Many phenotypic differences among related species are more likely to result from gene expression divergence rather than from non-synonymous mutations. In this regard, cis-regulatory mutations play an important part in generating functionally significant variation. Some proposed mechanisms that explore the role of cis-regulatory mutations in gene expression divergence involve microsatellites. Microsatellites exhibit high mutation rates and are abundant in both coding and non-coding regions and could influence gene function and products. Here we tested the hypothesis that microsatellites contribute to gene expression divergence among species with 50 individuals from nine closely related Helianthus species using an RNA-seq approach. Differential expression analyses of the transcriptomes revealed that genes containing microsatellites in non-coding regions (UTRs and introns) are more likely to be differentially expressed among species when compared to genes with microsatellites in the coding regions and transcripts lacking microsatellites. We detected a greater proportion of shared microsatellites in 5’UTRs and coding regions compared to 3’UTRs and non-coding transcripts among Helianthus spp. Further, allele frequency differences measured by pairwise FST at single nucleotide polymorphisms (SNPs), indicate greater genetic divergence in transcripts containing microsatellites compared to those lacking microsatellites. A gene ontology (GO) analysis revealed that microsatellite-containing differentially expressed genes are significantly enriched for GO terms associated with regulation of transcription and transcription factor activity. Collectively, our study provides compelling evidence to support the role of microsatellites in gene expression divergence.