RESUMO
Jackfruit (Artocarpus heterophyllus Lam.) is the national fruit of Bangladesh and produces fruit in the summer season only. However, jackfruit is not commercially grown in Bangladesh because of an extremely high variation in fruit quality, short seasonal fruiting (June-August) and susceptibility to abiotic stresses. Conversely, a year-round high yielding (ca. 4-fold higher than the seasonal variety) jackfruit variety, BARI Kanthal-3 developed by the Bangladesh Agricultural Research Institute (BARI) derived from a wild accession found in Ramgarh of Chattogram Hiltracts of Bangladesh, provides fruits from September to June. This study aimed to generate a draft whole-genome sequence (WGS) of BARI Kanthal-3 to obtain molecular insights including genes associated with year-round fruiting trait of this important unique variety. The estimated genome size of BARI Kanthal-3 was 1.04-gigabase-pair (Gbp) with a heterozygosity rate of 1.62%. De novo assembly yielded a scaffolded 817.7 Mb genome while a reference-guided approach, yielded 843 Mb of genome sequence. The estimated GC content was 34.10%. Variant analysis revealed that BARI Kanthal-3 included 5.7 M (35%) and 10.4 M (65%) simple and heterozygous single nucleotide polymorphisms (SNPs), and about 90% of all these polymorphisms are in inter-genic regions. Through BUSCO assessment, 97.2% of the core genes were represented in the assembly with 1.3% and 1.5% either fragmented or missing, respectively. By comparing identified orthologous gene groups in BARI Kanthal-3 with five closely and one distantly related species of 10,092 common orthogroups were found across the genomes of the six species. The phylogenetic analysis of the shared orthogroups showed that A. heterophyllus was the closest species to BARI Kanthal-3 and orthogroups related to flowering time were found to be more highly prevalent in BARI Kanthal-3 compared to the other Arctocarpus spp. The findings of this study will help better understanding the evolution, domestication, phylogenetic relationships, year-round fruiting of this highly nutritious fruit crop as well as providing a resource for molecular breeding.
RESUMO
BACKGROUND: Aegle marmelos (commonly known as Bael, golden apple) was formerly described to have anti-hyperglycemic activity. The present study aimed to explore the possible effects, in depth, of A. marmelos extracts on carbohydrate absorption, glucose utilization, and α-amylase inhibition and insulin content in pancreases of type 2 diabetic rats. METHODS: This research begins with fasting blood glucose and oral glucose tolerance test (OGTT) to evaluate the primary anti-hyperglycemic effect in chemically induced type 2 diabetic rats. Furthermore, the plasma insulin concentration and serum glucose level were studied, which include measuring the sucrose content in six different segments of the gastrointestinal (GI) tract of the rats following oral sucrose feeding. An in situ, perfused, intestinal model in rats and glucose-fiber binding assay were conducted to find the effects of A. marmelos extracts on glucose absorption. Extract effects on carbohydrate breakdown, intestinal disaccharidase enzyme activity, and α-amylase inhibition were assessed. Effect on GI motility was evaluated using BaSO4 milk traverse test. RESULTS: Treatment of extracts suppressed blood glucose elevation after oral sucrose (2.5 g/kg) administration and significantly (p<0.05) improved oral glucose tolerance in type 2 diabetic rats. Aegle marmelos extracts showed remarkable (p<0.05) changes in plasma insulin secretion at 30 min and 60 min, respectively. A noticeable reduction in glucose absorption was observed in the in situ perfused rat intestinal model at two different doses (250 and 500 mg/kg). The extract was also found to inhibit the action of both α-amylase and intestinal disaccharidase enzyme, and this study was affirmed again by the sucrose malabsorption test, where sucrose digestion was inhibited throughout the length of the GI tract. During this chronic study, body mass of rats became normal and their polydipsic and polyphagic conditions were ameliorated also. CONCLUSIONS: The findings demonstrate that anti-hyperglycemic activity of A. marmelos is mediated by the inhibition of carbohydrate digestion and absorption, and improvement of insulin action to uptake glucose in peripheral tissue. Additional study is required to correlate A. marmelos extracts' specific mechanism of glucose-fiber binding capacity and glucose transporters.