Biology subjects

Gopaulchan, D.

Publications and source records attributed to Gopaulchan, D..

3 recordsLinked to original sources

bioRxiv2024

Persistent legacy effects on soil metagenomes facilitate plant adaptive responses to drought

Both chronic and acute drought alter the composition and physiology of soil microbiota by selecting for functional traits that preserve fitness in dry conditions. Currently, little is known about how the resulting precipitation legacy effects manifest at the molecular and physiological levels and how they influence neighboring plants, especially in the context of subsequent drought. We characterized metagenomes of six prairie soils spanning a steep precipitation gradient in Kansas, USA. By statistically controlling for variation in soil porosity and elemental profiles, we identified bacterial taxa and functional gene categories associated with precipitation. This microbial precipitation legacy persisted through a 5-month-long experimental drought and mitigated the negative physiological effects of acute drought for a wild grass species that is native to the precipitation gradient, but not for the domesticated crop species maize. In particular, microbiota with a low-precipitation legacy altered transcription of a subset of host genes that mediate transpiration and intrinsic water use efficiency during drought. Our results show how long-term exposure to water stress alters soil microbial communities with consequences for the drought responses of neighboring plants.

microbiology↗

bioRxiv2023

Impact of whole-genome duplications on structural variant evolution in the plant genus Cochlearia

Polyploidy, the result of whole-genome duplication (WGD), is a major driver of eukaryote evolution. All angiosperms have undergone ancient WGDs, and today stable polyploids account for a substantial portion of both wild and domesticated plant species. Despite its centrality in evolution, WGD is a hugely disruptive mutation, and we still lack a clear understanding of its fitness consequences. Here, we study whether WGD results in greater diversity of genomic structural variants (SVs) and how this influences evolutionary dynamics in nature. Using a set of long-read sequenced samples from the plant genus Cochlearia (Brassicaceae), which contains diploids and a recent ploidy series up to octoploid, we show that masking of recessive mutations due to WGD has led to a substantial and progressive accumulation of genic SVs across four ploidy levels. Such SVs likely constitute a genetic load and thus reduce the adaptive potential of polyploid populations. However, this SV accumulation also provides a rich pool of standing genetic variation upon which selection may act in novel environments. By constructing a graph-based pangenome for Cochlearia, we identify SVs in hundreds of samples and study the genomic basis of environmental adaptation. We find putatively beneficial SVs involved in pathogen resistance, root development, and salt tolerance, many of which are unique to polyploids. Finally, we explore the adaptive landscapes of SVs and SNPs, identify geographical regions where SVs make novel contributions to adaptive variation, and predict that the role of SVs in environmental adaptation increases due to rapid climate change.

evolutionary biology↗

bioRxiv2020

Comparative transcriptomic analysis reveals key components controlling spathe color in Anthurium andraeanum (Hort.)

Anthurium andraeanum (Hort.) is an important ornamental in the tropical cut-flower industry. However, there is currently not enough information to establish a clear connection between the genetic model(s) proposed and the putative genes involved in the differentiation between colors. In this study, 18 cDNA libraries related to the spathe color and developmental stages of A. andraeanum cut-flowers were characterized by transcriptome sequencing technology. For the de novo transcriptome, a total of 114,334,082 primary sequence reads were obtained from the Illumina sequencer and were assembled into 151,652 unigenes. Approximately 58,476 transcripts were generated and used for comparative transcriptome analysis between three varieties that differ in spathe color ( Sasha (white), Honduras (red), and Rapido (purple)). A large number of differentially expressed genes (8,324) that were potentially involved in multiple biological and metabolic pathways were identified, including the flavonoid and anthocyanin biosynthetic pathways. Our results showed that chalcone synthase (CHS) and flavonoid 3-hydroxylase (F3H) were the main genes differentially expressed in the white/red/purple comparison. We also identified a differentially expressed cytochrome P450 in the late developmental stage of the purple spathe that appeared to determine the difference between the red- and purple-colored spathes. Additionally, putative MYB-domain protein candidates that could be responsible for the control of the biosynthetic pathway were identified. The results provided basic sequence information for future research on spathe color, which have important implications for breeding strategies in this ornamental. Core ideasO_LIRNA-seq was performed on three anthurium varieties. C_LIO_LIGene expression was compared for developmental stage and spathe color. C_LIO_LIDifferentially expressed unigenes were identified. C_LIO_LIPutative MYB-domain protein candidates of the anthocyanin biosynthetic pathway were identified. C_LI

genomics↗