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Collins, Cassandra

Publications and source records attributed to Collins, Cassandra.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Sugar Relese Supplementary Text and Figures

Phylogenetic tree of GAUT Protein Family and gene model, RNAi construct, and relative transcript abundance of GAUT4 in switchgrass, rice and poplar knockdown (KD) lines.

bio engineered↗
DOE OSTI2019

Multitrait genome–wide association analysis of Populus trichocarpa identifies key polymorphisms controlling morphological and physiological traits

Genome–wide association studies (GWAS) have great promise for identifying the loci that contribute to adaptive variation, but the complex genetic architecture of many quantitative traits presents a substantial challenge.We measured 14 morphological and physiological traits and identified single nucleotide polymorphism (SNP)–phenotype associations in a Populus trichocarpa population distributed from California, USA to British Columbia, Canada. We used whole–genome resequencing data of 882 trees with more than 6.78 million SNPs, coupled with multitrait association to detect polymorphisms with potentially pleiotropic effects. Candidate genes were validated with functional data.Broad–sense heritability (H2) ranged from 0.30 to 0.56 for morphological traits and 0.08 to 0.36 for physiological traits. In total, 4 and 20 gene models were detected using the single–trait and multitrait association methods, respectively. Several of these associations were corroborated by additional lines of evidence, including co–expression networks, metabolite analyses, and direct confirmation of gene function through RNAi.Multitrait association identified many more significant associations than single–trait association, potentially revealing pleiotropic effects of individual genes. Furthermore, this approach can be particularly useful for challenging physiological traits such as water–use efficiency or complex traits such as leaf morphology, for which we were able to identify credible candidate genes by combining multitrait association with gene co–expression and co–methylation data.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

A New Calmodulin-Binding Protein Expresses in the Context of Secondary Cell Wall Biosynthesis and Impacts Biomass Properties in Populus

Here, a greater understanding of biosynthesis, signaling and regulatory pathways involved in determining stem growth and secondary cell wall chemistry is important for enabling pathway engineering and genetic optimization of biomass properties. The present study describes a new functional role of PdIQD10 , a Populus gene belonging to the IQ67-Domain1 family of IQD genes, in impacting biomass formation and chemistry. Expression studies showed that PdIQD10 has enhanced expression in developing xylem and tension-stressed tissues in Populus deltoides . Molecular dynamics simulation and yeast two-hybrid interaction experiments suggest interactions with two calmodulin proteins, CaM247 and CaM014, supporting the sequence-predicted functional role of the PdIQD10 as a calmodulin-binding protein. PdIQD10 was found to interact with specific Populus isoforms of the Kinesin Light Chain protein family, shown previously to function as microtubule-guided, cargo binding and delivery proteins in Arabidopsis . Subcellular localization studies showed that PdIQD10 localizes in the nucleus and plasma membrane regions. Promoter-binding assays suggest that a known master transcriptional regulator of secondary cell wall biosynthesis (PdWND1B) may be upstream of an HD-ZIP III gene that is in turn upstream of PdIQD10 gene in the transcriptional network. RNAi-mediated downregulation of PdIQD10 expression resulted in plants with altered biomass properties including higher cellulose, wall glucose content and greater biomass quantity. Furthermore, these results present evidence in support of a new functional role for an IQD gene family member, PdIQD10 , in secondary cell wall biosynthesis and biomass formation in Populus.

09 BIOMASS FUELS↗