Direct Shoot Regeneration from Mature Leaf Explants of Sphaeranthus indicus L., A Multipurpose Medicinal Plant

A rapid and reproducible protocol for in vitro regeneration of Sphaeranthus indicus (Asteraceae), a medicinal herb has been established. Leaf segments isolated from mature plants were cultured on MS medium with different concentrations of 6-benzyladenine (2.2, 4.4, 6.6 and 8.8 µM) or kinetin (1.3, 2.3, 4.6 and 6.9 µM). Inclusion of IAA into BA supplemented medium triggered a high frequency of regeneration response from leaf explants. Maximum number of shoots (12 ±1.15) with highest shoot length (3.0 ±0.73) were obtained directly (without intervening callus phase) from the leaf explants using combination of BA (4.4 µM) and IAA (1.71 µM) within 3-4 week of culture. The elongated shoots were rooted on MS medium fortified with IBA (2.46 µM).The regenerated plantlets were successfully hardened on earthen pots after proper acclimatization under greenhouse conditions

Genome-Wide Identification and Characterization of AP2/ERF Transcription Factor Family Genes in Oil Palm under Abiotic Stress Conditions

The AP2/ERF transcription factor family members play crucial roles in controlling plant growth and development, as well as responses to various abiotic stresses. Genome-wide identification and characterization of AP2/ERF genes has not yet been carried out in the oil palm genome. In the present work, we reported the occurrence of 172 EgAP2/ERFs (AP2, ERF, RAV & Soloist members) through genome-wide identification. Phylogenetic analysis was used to divide them into four groups, including: 34 AP2, 131 ERF, 5 RAV, and 2 Soloist gene family members. All 172 AP2/ERF members were unevenly distributed across 16 chromosomes of oil palm. Gene duplication analysis elucidated the tandem duplication of AP2/ERFs on chromosome blocks of the oil palm genome during evolution. Gene structure as well as conserved motif analysis demonstrated the conserved nature of intron/exon organization and motifs among the AP2/ERF genes. Several cis-regulatory elements—related to hormone, stress, and defense responses—were identified in the promoter regions of AP2/ERFs. Tissue-specific expression of 172 AP2/ERFs in five different tissues of oil palm was also revealed by heatmap analysis using the available transcriptome data. Finally, abiotic stress (salinity, cold & drought)-responsive AP2/ERFs in the oil palm genome were validated through qPCR analysis. Our study provided valuable information on oil palm AP2/ERF superfamily members and dissected their role in abiotic stress conditions

Efficient in vitro direct shoot organogenesis from seedling derived split node explants of maize (Zea mays L.)

Maize is one of the important cereal crops around the world. An efficient and reproducible regeneration protocol via direct organogenesis has been established using split nodes as ex-plants derived from 7 to 10 day old in vitro grown seedlings. Surface sterilized maize seeds were germinated on MS medium lacking plant growth regulators. Nodal sections of 7–10 day old seedlings were isolated, split longitudinally into two halves and cultured on regeneration medium containing different concentrations of 6-benzyladenine (2.20, 4.40, 6.60, 8.80, 11.0 and 13.2 μM) or kinetin (2.32, 4.65, 6.97, 9.29, 11.6 and 13.9 μM). Inclusion of 8.80 μM BA into MS supplemented medium triggered a high frequency of regeneration response from split node explants with a maximum number of shoots (12.0 ± 1.15) and the highest shoot length (3.0 ± 0.73) was obtained directly (without an intervening callus phase) within 4 weeks of culture. Further shoot elongation was achieved on medium containing 4.40 μM BA. The elongated micro shoots were rooted on MS medium fortified with 1.97 μM indole-3-butyric acid. The regenerated plantlets with roots were successfully hardened on earthen pots after proper acclimatization under greenhouse conditions. This new efficient regeneration method provides a solid foundation for genetic manipulation of maize for biotic and abiotic stresses and to enhance the nutritional values

Progress in Tissue Culture and Genetic Transformation of Oil Palm: An Overview

Oil palm (Elaeis guineensis, Jacq.) is a prominent vegetable-oil-yielding crop. Cultivating high-yielding oil palm with improved traits is a pre-requisite to meet the increasing demands of palm oil consumption. However, tissue culture and biotechnological approaches can resolve these concerns. Over the past three decades, significant research has been carried out to develop tissue culture and genetic transformation protocols for oil palm. Somatic embryogenesis is an efficient platform for the micropropagation of oil palm on a large scale. In addition, various genetic transformation techniques, including microprojectile bombardment, Agrobacterium tumefaciens mediated, Polyethylene glycol mediated mediated, and DNA microinjection, have been developed by optimizing various parameters for the efficient genetic transformation of oil palm. This review mainly emphasizes the methods established for in vitro propagation and genetic transformation of oil palm. Finally, we propose the application of the genome editing tool CRISPR/Cas9 to improve the various traits in this oil yielding crop

Oil Palm Breeding in the Modern Era: Challenges and Opportunities

Oil palm, a cross-pollinated crop with long generation time, poses a lot of challenges in achieving sustainable oil palm with high yield and quality. The African oil palm (Elaeis guineensis Jacq.) is the most productive and versatile oil-yielding crop in the world, producing more than any other oil-yielding crop. Despite recent challenges, such as stress tolerance, superior oil quality, disease tolerance, and the need for new market niches, there is a growing need to explore and develop new varieties with high yield potential and the genetic diversity required to maintain oil palm yield stability. Breeding is an indispensable part of producing high-quality planting materials to increase oil palm yield. Biotechnological technologies have transformed conventional plant breeding approaches by introducing novel genotypes for breeding. Innovative pre-breeding and breeding approaches, such as identifying candidate genes in wild or land races using genomics tools, can pave the way for genetic improvement in oil palm. In this review, we highlighted the modern breeding tools, including genomics, marker-assisted breeding, genetic engineering, and genome editing techniques in oil palm crops, and we explored certain concerns connected to the techniques and their applications in practical breeding

Cascade photocaging of diazeniumdiolate: a novel strategy for one and two photon triggered uncaging with real time reporting

We report a new strategy, viz. cascade photocaging, for protecting diethylamine diazeniumdiolate (O2-position), a light sensitive molecule. Upon photolysis, the cascade photocage at first releases the light activatable linker (latent fluorophore) O2-caged diazeniumdiolate, which undergoes spontaneous 1,8-elimination, triggering the release of the diazeniumdiolate anion and the fluorophore

Three-arm, biotin-tagged carbazole-dicyanovinyl-chlorambucil conjugate: simultaneous tumor targeting, sensing, and photoresponsive anticancer drug delivery

The design, synthesis and in vitro biological studies of a biotin-carbazole-dicyanovinyl-chlorambucil conjugate (Bio-CBZ-DCV-CBL; 6) are reported. This conjugate (6) is a multifunctional single-molecule appliance composed of a thiol-sensor DCV functionality, a CBZ-derived phototrigger as well as fluorescent reporter and CBL as the anticancer drug and Bio as the cancer-targeting ligand. In conjugate 6, the DCV bond undergoes a thiol-ene click reaction at pH<7 with intracellular thiols, thereby shutting down internal charge transfer between the donor CBZ and acceptor DCV units, resulting in a change of the fluorescence color from green to blue, and thereby, sensing the tumor microenvironment. Subsequent photoirradiation results in release of the anticancer drug CBL in a controlled manner

Photocaging of Single and Dual (Similar or Different) Carboxylic and Amino Acids by Acetyl Carbazole and its Application as Dual Drug Delivery in Cancer Therapy

A new fluorescent photoremovable protecting group (FPRPG) based on acetylcarbazole framework has been explored for the first time release of single and dual (similar or different) substrates from single chromophore. Mechanistic studies of the photorelease process revealed that photorelease of two (similar or different) substrates from acetyl carbazole proceeds via a stepwise pathway. Further, we constructed photoresponsive dual drug delivery system (DDS) to release two different anticancer drugs (caffeic acid and chlorambucil, 1 equiv each). In vitro study reveals that our DDS exhibit excellent properties like biocompatibility, cellular uptake, and photoregulated dual drug release