Transcriptional foliar profile of the C3-CAM bromeliad Guzmania monostachia

Abstract

Guzmania monostachia is an epiphytic tank bromeliad that displays the inducible CAM photosynthesis under stressful conditions and had the highest stomata density in the leaf apex, while the base portion has the highest density of trichomes, which are specialized structures used to acquire water and nutrients from the tank solution. In order to correlate the genetic factors behind these morpho-physiological characteristics along the leaf blade of G. monostachia, a comparative transcriptome analysis was performed to identify the functional enriched pathways and unigenes that could play a role in the apical, middle and basal leaf portions. A total of 653 million reads were used for de novo transcriptome assembly, resulting in 48,051 annotated unigenes. Analysis of differentially expressed genes (DEGs) among distinct leaf regions revealed that 806 DEGs were upregulated in the apex compared to the middle portion, while 9685 DEGs were upregulated in the apex and 9784 DEGs were upregulated in the middle portions compared to the base. Our outcomes correlated some DEGs and identified unigenes with their physiological functions, mainly suggesting that the leaf apex was related to the regulation of stomatal movement, production of chlorophyll, cellular response to stress, and H2O2 catabolic process. In contrast, the middle portion showed DEGs associated with the transport of amino acids. Furthermore, DEGs from the leaf base were mainly correlated with responses to nutrients and nitrogen compounds, regulation of potassium ion import, response to water deprivation, and trichome branching, indicating that, at least in part, this leaf portion can replace some of the root functions of terrestrial plants. Therefore, possibly candidate unigenes and enriched pathways presented here could be prospected in future experimental work, opening new possibilities to bioengineer non-inducible CAM plants and/or improve the fertilization use efficiency by increasing leaf nutrient acquisition of crop plants.

Integrated analysis of DNA methylome and transcriptome reveals epigenetic regulation of CAM photosynthesis in pineapple

“…In Guzmania monostachia, people found that the up-regulated genes of the leaf tip are mainly enriched in the regulation of stomatal movement, tryptophan metabolic process, chlorophyll biosynthetic process, and aspartate metabolic process. However, the up-regulated genes of leaf base are mainly related to response to water deprivation, starch, and sucrose metabolic processes [ 41 ]. These results are consistent with our findings, indicating that core CAM-related genes and steps between inducible and constitutive CAM plants are similar.…”

Transcriptomic and Biochemical Analysis Reveal Integrative Pathways Between Carbon and Nitrogen Metabolism in Guzmania monostachia (Bromeliaceae) Under Drought

“…Total RNA was extracted using the PureLink ® RNA Mini Kit (Ambion) according to the manufacturer's protocol. RNA concentration, quality, and integrity were checked as described in Mercier et al (2019). Samples with integrity number ≥6.5 were pooled to generate libraries using TruSeq RNA Sample Preparation Kit, Set A (Illumina Inc., United States).…”

“…Samples with integrity number ≥6.5 were pooled to generate libraries using TruSeq RNA Sample Preparation Kit, Set A (Illumina Inc., United States). Paired-end sequences were generated as described by Mercier et al (2019), and only high-quality sequences (with average PhredScore over 24) were used. Sequence normalization and de novo transcriptome assembly were performed using Trinity (Grabherr et al, 2011;Haas et al, 2013) as described in Mercier et al (2019), and the reads were deposited at NCBI at the Bioproject ID PRJNA532595.…”

“…Paired-end sequences were generated as described by Mercier et al (2019), and only high-quality sequences (with average PhredScore over 24) were used. Sequence normalization and de novo transcriptome assembly were performed using Trinity (Grabherr et al, 2011;Haas et al, 2013) as described in Mercier et al (2019), and the reads were deposited at NCBI at the Bioproject ID PRJNA532595. Guzmania monostachia transcripts were annotated using the Viridiplantae (taxa ID 33090, VP) and Monototyledons (taxa ID 4447, MC) database through the BLAST suite (Camacho et al, 2008) and Blast2GO 1 (Conesa et al, 2005).…”

“…Considering N assimilation, the highest activity of glutamine synthetase (GS) was found at the apex, while urease can be found at the base, indicating the importance of the apical foliar portion for amino acid production (Gonçalves et al, 2020b). Transcriptional analysis of G. monostachia leaf showed that the apex and middle portion had differentially expressed genes related to amino acid metabolism and photosynthesis, while the base showed responses to nutrients, particularly N (Mercier et al, 2019).…”