Genotype-dependent changes of gene expression during somatic embryogenesis in oil palm hybrids (Elaeis oleifera x E. guineensis)

Abstract

To understand the molecular processes triggered during the different steps of somatic embryogenesis (SE) in oil palm, the expression of 19 genes associated to SE identified in proteomic and transcriptomic studies was investigated by qRT-PCR. To evaluate the differential expression of these genes, two interspecific hybrid genotypes (Elaeis oleifera x Elaeis guineensis) contrasting for the acquisition of embryogenic competence were used. Aclorophyllated leaves of both hybrids, one responsive (B351733) and the other non-responsive (B352933) to SE were submitted to callus induction and collected at different time points: 0 (before induction), 14, 30, 90 and 150 days of callus induction (doi). The results obtained showed that all evaluated genes were downregulated at 14 doi in the responsive genotype when compared to the non-responsive. It was also possible to observe that most of the genes changed their expression behavior at 30 doi and were upregulated thereafter until 150 doi, with the exception of the pathogenesis-related PRB1-3-like (PRB1-3) gene, which did not show differential expression at 30 doi and was downregulated at 90 and 150 doi when compared to the non-responsive hybrid. These results indicate that 30 doi is a turning point in gene expression, probably associated to embryogenic competence acquisition. We also show that the expression behavior of the responsive genotype is more stable than that of the non-responsive when the different induction time points are compared to 0 doi (before induction). Moreover, the results obtained in this study corroborate our hypothesis that the regulation of genes involved in the control of oxidative stress and energy metabolism are crucial for the acquisition of embryogenic competence in oil palm.

A robust workflow for indirect somatic embryogenesis and cormlet production in saffron (Crocus sativus L.) and its wild allies; C. caspius and C. speciosus

“…In the present study, the SERK gene was induced in embryogenic calli but not in non-embryogenic calli which is in agreement with the previous report (Santos et al, 2018). The higher expression levels of the SERK gene in C. sativus may explain the observed higher callus induction frequencies in C. sativus and its overall in vitro culture efficiency.…”

Identification of a predominant genotype of Mycobacterium tuberculosis in Brazilian indigenous population

“…This mutation falls outside the QRDR and has not been associated with fluoroquinolone resistance 46 . Whether it led to drug resistance in patients is unknown, but it is important to note that while indigenous patients are not treated with fluoroquinolones for TB in Brazil, drugs in this major group are regularly administered for other ailments such as pneumonia, foodborne diseases, and urinary tract infections caused by a wide variety of bacteria such as methicillin-resistant Staphylococcus aureus 47 , Enterobacteriaceae 48 , Pseudomonas aeruginosa 49 , and Salmonella 50 . It is possible that the use of fluoroquinolones for other conditions in parallel with endemic TB has led to the development of unique circulating TB strains.…”

Protuberances are organized distinct regions of long-term callus: histological and transcriptomic analyses in kiwifruit

“…Several genes involved in the carbohydrate metabolism pathways in the PTs were strongly up-regulated, for example, the genes involved in starch synthesis. The initiation of organogenesis required an accumulation of storage substances, and energy mobilization has been reported to play an important role in shoot formation (Carciofi et al 2012 ; Santos et al 2018 ; Lee and Huang 2019 ). The expression of genes connected with modifying the existing cell wall and its integrity (Shigeyama et al 2016 ) together with suberin biosynthesis, suggest the reorganization of cells towards the formation of other types of structures.…”

“…Changes in carbohydrate metabolism accompanied by higher mRNA transcription levels of the genes involved in starch synthesis have been found, e.g., in the embryogenic callus in Picea balfouriana (Li et al 2014 ) and the organogenic, highly regenerable callus in rice (Lee and Huang 2019 ). Increased expression of GBSS1 was detected in the embryogenic callus in oil palm (Santos et al 2018 ). GBSS1 enzyme is required for the starch biosynthesis pathway, especially for the elongation of the amylose polymer, and it is closely associated with the formation of starch granules.…”