Starch, a vital dietary component and crucial for bio-ethanol generation, is synthesized by plants during photosynthesis. Augmenting starch output holds promise for human and animal nutrition, as well as bioenergy. Our previous work involved cloning the homolog gene DRM2 from Purslane and subsequently overexpressing PoDRM2 in Arabidopsis. Comparative analysis between wild-type Columbia and homozygous PoDRM2 transgenic lines revealed a substantial increase in plant size and nearly a 90% rise in fresh biomass per plant in PoDRM2 lines, indicating a potentially heightened efficiency in photosynthesis. We conducted further investigations into starch synthesis and accumulation in leaves. Iodine staining revealed that PoDRM2 transgenic Arabidopsis lines accumulated significantly more starch than the control under both dark and light conditions. Additionally, total carbohydrates in the leaves of transgenic lines more than doubled that of the wild type. Furthermore, PoDRM2 lines exhibited higher chlorophyll content compared to the control. These findings strongly indicate that PoDRM2 serves as a crucial regulator of starch accumulation. PoDRM2, encoding a methyltransferase, was implicated in altering the methylation status of over 2,500 genes through genome-wide bisulfite sequencing. Notably, 55 out of 61 genes involved in the photosynthesis pathway were affected, underscoring the significant role of DNA methylation in regulating starch accumulation and photosynthesis in plants.
Plant whole genome sequencing provides detailed information on gene content, genome organization, and evolutionary relationships as well as supports biotechnological applications such as gene editing. The first 3X draft genome sequence of papaya based on whole genome shotgun reads from the transgenic ‘SunUp’ papaya cultivar was published in 2008. Since then, advancements in sequencing and whole genome assembly enabled a near complete sequence of ‘SunUp’ and a detailed picture of events resulting from particle gun-mediated transformation. With current technology, the 372 Mb genome size of papaya makes it tractable for routine whole genome sequencing to characterize different cultivars and molecular events. In this study, we improved ease and speed of preparation, efficiency of recovery, and DNA quality through a combination of classical and contemporary plant nuclei or high molecular weight DNA isolation methods. Leveraging Hi-Fi sequencing and Hi-C technology, we achieved rapid chromosome-level sequence assembly of two local Hawaiian cultivars, Kapoho and Waimanalo. The assembled genomes of Kapoho and Waimanalo spanned 341.6 Mb and 337.4 Mb, respectively, with a total of 20,343 and 20,165 annotated protein-coding genes.
The genus Miscanthus is considered an ideal choice for both ornamental and biofuel purposes, owing to its appealing aesthetics and significant potential for high-energy biomass production. Traditional breeding efforts in Miscanthus have predominantly focused on enhancing nutrient efficiency and tolerance to both biotic and abiotic stresses. However, these endeavors are often time-consuming. The emergence of plant genome editing technologies has opened up a new and efficient avenue for Miscanthus breeding. These innovative techniques hold promise for accelerating the breeding process, allowing for more rapid and targeted improvements in desired traits. The development of an efficient plant regeneration system is crucial for the application of modern genome editing technologies in Miscanthus breeding and for achieving large-scale biomass production. Among the Miscanthus species, Miscanthus sinensis poses a particular challenge in tissue culture regeneration. In this report, we present an effective system for callus induction and regeneration in Miscanthus sinensis. Callus was induced from the stems of in vitro-cultured Miscanthus sinensis 'Gracillimus' using a modified MS media supplemented with varying levels of 2,4-D. Regeneration-competent callus was achieved through continuous selection on the callus maintenance/selection medium over a period of 6 months. Remarkably, 100% of the callus successfully regenerated new shoots on a modified MS medium containing Benzylaminopurine (6-BA) and α-Naphthaleneacetic acid (NAA). This marks the first efficient 'Gracillimus' regeneration system using in vitro culture as the starting material. The established system demonstrates a high potential for the micropropagation of Miscanthus sinensis 'Gracillimus' with a propagation rate of 3.5. Currently, efforts are underway for genome editing of Miscanthus sinensis utilizing this established system.
Blueberry (Vaccinium sp. L.) is one of the most important fruit crops from the Ericaceae family and the highbush blueberry (Vaccinium corymbosum) is the most widely grown species. It's popularity is increasing day-by-day because of their unique flavor and rich nutritional content. Consequently, significant efforts have been made to develop superior cultivars with high yield, biotic and abiotic stress resistance using conventional breeding. However, due to high heterozygosity, polyploidy and long juvenile period, traditional breeding approaches can often be tedious and time consuming. Therefore, there is need to integrate modern precision breeding tools with traditional ones, to accelerate blueberry crop improvement. However, the success of novel biotechnological tools like gene editing and conventional transformation relies on successful shoot regeneration system. Many studies in blueberry show a lack of reliable regeneration protocols and their genotype-dependency. Furthermore, most of the reported regeneration studies have been conducted on northern highbush blueberry (NHB) cultivars. Therefore, the current study aims to develop shoot regeneration protocol for seven important southern highbush blueberry (SHB) cultivars (Colossus, Optimus, Albus, Arcadia, Keecrsip, FL 14-242
