Phenotypical Expression of Maize Seedlings from Lines with the “Tallos Gemelos” Trait

In the Colegio de Postgraduados in Mexico, we have generated lines of maize (Zea mays L.) with the particularity that from a seed two or more stalks emerge and develop normally, calling that character “tallos gemelos.” This trait possibly modifies the proportions of the constituent tissues of the seed and could increase the nutritional and nutraceutical quality of the grain. The aim of this study was to evaluate the germination percentage and quantify and describe the types of phenotypic expression of seedling with twin stalks in the lines. 100 seeds of each of the 26 S5 lines tested were used. At 15 days after planting in a greenhouse, the seedlings were classified based on their morphology. The results showed that, on average, the lines had 81.3% of emergence and 51% of twin stalks. Eight types of phenotypic expression in seedlings were identified and described with the character “tallos gemelos”; Type II showed the highest proportion (59.5%). The phenotypical expressions identified in seedlings with the “tallos gemelos” trait are evidence of epigenetic mechanisms, since they present one of the features of epimutants, which is that they are reversible, that is; they can return to the original phenotype, in the present circumstance to normal plants (single stalk).

Rhizogenesis in Cell Suspension Culture from Mango Ginger: A Source of Isosorbide and n-Hexadecanoic Acid

Curcuma amada Roxb. belongs to the monocotyledonous family Zingiberaceae. It is commonly known as mango ginger and used as a spice and valuable medicine. In this study, adventitious roots of C. amada have been successfully established from cell suspension culture. The highest percentage of adventitious root production was obtained from friable callus derived cell suspension culture. The culture conditions of adventitious root were optimized and the maximum adventitious root production was obtained in half strength MS liquid medium containing 0.3 mg L−1 IBA along with 3% of sucrose after 5 weeks of culture. Among the different initial inoculum density, the best culture condition for root growth occurred at 10 g FW of initial inoculum density. GC-MS analysis revealed that the in vitro raised adventitious roots containing two valuable bioactive compounds, isosorbide and n-hexadecanoic acid. The outcome of the present work will be helpful for the large scale cultivation of adventitious roots for the production of valuable bioactive compounds.

Contribution to the Macrophytic Typology of Belgian Reference Watercourses

The objective of the study is to create a typology of macrophytes for the reference watercourses of the Meuse River catchment basin in Wallonia as a step towards the implementation of the European Water Framework Directive. The 50 sites studied are the object of a physicochemical and environmental characterization followed by a floristic survey (phanerogams, mosses, liverworts, and macroalgae). Six clusters of watercourses with their characteristic species are highlighted by two-way clustering and indicator species. The abundance of phanerogams in some watercourses of the Arden region is not only linked to light intensity but also depends on the degree of slope and the nature of the geological substrate.

Shaping the Arabidopsis Transcriptome through Alternative Splicing

Alternative splicing is a molecular tool of the cell to generate more than one messenger RNA from the same gene. Through variable combinations of exons blueprints for different proteins are assembled from one and the same pre-messenger RNA, thus increasing the complexity of the proteome. Moreover, through alternative splicing different transcript variants with different stabilities and different regulatory motifs can be generated, leading to variation in the transcriptome. The importance of alternative splicing in plants has been increasingly recognized in the last decade. Alternative splicing has been found during abiotic and biotic stress and during development. Here, recent advancements in the understanding of alternative splicing in higher plants are presented. Mechanistic details and functional consequences of alternative splicing are discussed with a focus on the model plant Arabidopsis thaliana.

Radiation Processed Carrageenan Improves Plant Growth, Physiological Activities, and Alkaloids Production in Catharanthus roseus L.

Catharanthus roseus (L.) G. Don (Apocynaceae) is a medicinal plant that produces indole alkaloids used in cancer chemotherapy. Commercially important antineoplastic alkaloids, namely, vinblastine and vincristine, are mainly present in the leaves of C. roseus. Gamma-rays irradiated carrageenan (ICR) has been proven as plant growth promoting substance for a number of medicinal and agricultural plants. Considering the importance of ICR as a promoter of plant growth and alkaloids production in C. roseus, a pot experiment was carried out to explore the effect of ICR on the plant growth, physiological activities, and production of anticancer alkaloids in C. roseus at 120 and 150 days after planting (DAP). Foliar application of ICR (at 0, 20, 40, 60, 80, and 100 mg L−1) significantly improved the performance of C. roseus. 80 mg L−1 of ICR enhanced the leaf yield by 29.2 and 35.4% and the herbage yield by 32.5 and 37.4% at 120 and 150 DAP, respectively, over the control. The spray of ICR at 80 mg L−1 increased the yield of vinblastine by 64.3 and 65.0% and of vincristine by 75.5 and 77.0% at 120 and 150 DAP, respectively, as compared to the control.

Energy Cane: Its Concept, Development, Characteristics, and Prospects

Unlike conventional sugar cane (Saccharum spp.) energy cane is a cane selected to have more fiber than sucrose in its composition. This is obtained simply by altering the genetic contribution of the ancestral species of sugarcane using traditional breeding methods. The resulting key feature is a significant increase in biomass yield. This happens because accumulating sugar is not physiologically a simple process and results in penalty in the side of fiber and yield. This review paper describes the initial conception of fuel cane in Puerto Rico in the second half of 1970s, the present resurgence of interest in it, how to breed energy cane, and the main characteristics that make it one of the most favorable dedicated bioenergy crops. The present status of breeding for energy cane in the world is also reviewed. Its potential contribution to the renewable energy market is discussed briefly.

Arabinogalactan Glycosyltransferases: Enzyme Assay, Protein-Protein Interaction, Subcellular Localization, and Perspectives for Application

Arabinogalactan proteins (AGPs) are abundant extracellular proteoglycans that are found in most plant species and involved in many cellular processes, such as cell proliferation and survival, pattern formation, and growth, and in plant microbe interaction. AGPs are synthesized by posttranslational O-glycosylation of proteins and attached glycan part often constitutes greater than 90% of the molecule. Subtle altered glycan structures during development have been considered to function as developmental markers on the cell surface, but little is known concerning the molecular mechanisms. My group has been working on glycosylation enzymes (glycosyltransferases) of AGPs to investigate glycan function of the molecule. This review summarizes the recent findings from my group as for AtGalT31A, AtGlcAT14A-C, and AtGalT29A of Arabidopsis thaliana with a specific focus on the (i) biochemical enzyme activities; (ii) subcellular compartments targeted by the glycosyltransferases; and (iii) protein-protein interactions. I also discuss application aspect of glycosyltransferase in improving AGP-based product used in industry, for example, gum arabic.

In Vitro Mass Multiplication and Assessment of Genetic Stability of In Vitro Raised Artemisia absinthium L. Plants Using ISSR and SSAP Molecular Markers

The present investigations were made attempting to develop a rapid, reliable, and reproducible in vitro regeneration protocol for Artemisia absinthium L., a medicinal plant of Kashmir Himalayas. Out of several auxin-cytokinin combinations tested, Murashige and Skoog’s (MS) medium supplemented with 0.5 mgL−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mgL−1 kinetin (Kn) was found to be the best for the callus induction. On the other hand, 4.5 mgL−1 6-benzylaminopurine (BAP) and 0.5 mgL−1 1-α-naphthaleneacetic acid (NAA) in the medium resulted in maximum shoot induction from the callus. Similarly, BAP and NAA at a concentration of 1.5 mgL−1 and 0.5 mgL−1, respectively, proved to be the best for the multiple shoot induction from nodal explants. Numerous shoots were obtained from nodal explants after third subculture. In vitro rooting was maximum on medium containing indole-3-butyric acid (IBA) at 0.5 mgL−1. The genetic stability of the in vitro raised plants of Artemisia absinthium was assessed using the intersimple sequence repeat (ISSR) and sequence-specific amplification polymorphism (SSAP) molecular markers. Both markers were able to detect the somaclonal variations in the callus regenerated plants, while no variation was detected in the plants regenerated from the nodal explants. SSAP has been found to be more useful in detection of variability as compared to ISSR molecular marker. The results of present study concluded that the direct regeneration protocol will be useful for the production of true to type plants of this medicinally important plant. This will go a long way in reducing the pressure on the natural populations for the secondary metabolite production, especially for extraction of essential oils.

Aflatoxin Resistance in Maize: What Have We Learned Lately?

Aflatoxin contamination of maize grain is a huge economic and health problem, causing death and increased disease burden in much of the developing world and income loss in the developed world. Despite the gravity of the problem, deployable solutions are still being sought. In the past 15 years, much progress has been made in creating resistant maize inbred lines; mapping of genetic factors associated with resistance; and identifying possible resistance mechanisms. This review highlights this progress, most of which has occurred since the last time a review was published on this topic. Many of the needs highlighted in the last reviews have been addressed, and several solutions, taken together, can now greatly reduce the aflatoxin problem in maize grain. Continued research will soon lead to further solutions, which promise to further reduce and even eliminate the problem completely.

Function and Regulation of the Plant COPT Family of High-Affinity Copper Transport Proteins

Copper (Cu) is an essential micronutrient for all eukaryotes because it participates as a redox active cofactor in multiple biological processes, including mitochondrial respiration, photosynthesis, oxidative stress protection, and iron (Fe) transport. In eukaryotic cells, Cu transport toward the cytoplasm is mediated by the conserved CTR/COPT family of high-affinity Cu transport proteins. This outlook paper reviews the contribution of our research group to the characterization of the function played by the Arabidopsis thaliana COPT1–6 family of proteins in plant Cu homeostasis. Our studies indicate that the different tissue specificity, Cu-regulated expression, and subcellular localization dictate COPT-specialized contribution to plant Cu transport and distribution. By characterizing lack-of-function Arabidopsis mutant lines, we conclude that COPT1 mediates root Cu acquisition, COPT6 facilitates shoot Cu distribution, and COPT5 mobilizes Cu from storage organelles. Furthermore, our work with copt2 mutant and COPT-overexpressing plants has also uncovered Cu connections with Fe homeostasis and the circadian clock, respectively. Future studies on the interaction between COPT transporters and other components of the Cu homeostasis network will improve our knowledge of plant Cu acquisition, distribution, regulation, and utilization by Cu-proteins.