Transcriptomic Analysis Provides Insights into Grafting Union Development in Pecan (Carya illinoinensis)

Abstract

Pecan (Carya illinoinensis), as a popular nut tree, has been widely planted in China in recent years. Grafting is an important technique for its cultivation. For a successful grafting, graft union development generally involves the formation of callus and vascular bundles at the graft union. To explore the molecular mechanism of graft union development, we applied high throughput RNA sequencing to investigate the transcriptomic profiles of graft union at four timepoints (0 days, 8 days, 15 days, and 30 days) during the pecan grafting process. After de novo assembly, 83,693 unigenes were obtained, and 40,069 of them were annotated. A total of 12,180 differentially expressed genes were identified between by grafting. Genes involved in hormone signaling, cell proliferation, xylem differentiation, cell elongation, secondary cell wall deposition, programmed cell death, and reactive oxygen species (ROS) scavenging showed significant differential expression during the graft union developmental process. In addition, we found that the content of auxin, cytokinin, and gibberellin were accumulated at the graft unions during the grafting process. These results will aid in our understanding of successful grafting in the future.

Identification of miRNAs Associated with Graft Union Development in Pecan [Carya illinoinensis (Wangenh.) K. Koch]

“…Putative targets of miRNA were predicted by TargetFinder, and then annotated based on the databases of Nr (NCBI non-redundant protein sequences), Protein family (Pfam) and GO (Gene Ontology). The expression value of putative target genes were obtained from the supplementary materials of our previously published paper (http://www.mdpi.com/2073-4425/9/2/71/s1) [27].…”

Transcriptome Analysis of Oleoresin-Producing Tree Sindora Glabra and Characterization of Sesquiterpene Synthases

“…In an attempt to investigate the molecular basis of terpene biosynthesis in S. glabra , an RNA-seq approach was employed to sequence the stem transcriptome from high and low oil-yielding trees. After transcriptome assembly, the total number, N50 length and mean length of de novo assembled transcipts and unigenes of S. glabra were much higher than those recently reported in other non-model plants including Carya illinoinensis (Mo et al, 2018 ), Kandelia obovata (Hong et al, 2018 ), Kalopanax septemlobus (Han et al, 2018 ), Salvia officinalis (Ali et al, 2017 ), and Melaleuca alternifolia (Bustos-Segura et al, 2017 ), suggesting high accuracy and reliability of the sequencing data. Numerous annotated unigenes (61.9%) were found to be distributed in the Fabaceae family, which was reasonable since S. glabra belongs to the Caesalpinioideae subfamily that is included in the Fabaceae family.…”

Plasma membrane H+‐ATPase activity and graft success of breadfruit (Artocarpus altilis) onto interspecific rootstocks of marang (A. odoratissimus) and pedalai (A. sericicarpus)

“…), together with up‐regulation of PM ATPase genes at 8, 15 and 30 day after grafting (Mo et al . ). Up‐regulation of both PM H + ‐ATPase protein and genes was observed in the graft union of Hickory ( Carya cathayensis ; Qiu et al .…”