Central University of Kerala

About: Central University of Kerala is a education organization based out in Kāsaragod, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 556 authors who have published 881 publications receiving 7474 citations.

Late Holocene palaeovegetational and environmental changes inferred from organic geochemical proxies in sediments from Pookot Lake, southern India

Abstract: The sediments from Pookot Lake situated in the Sahyadri (Western Ghats) of southern India provided a record of palaeovegetation and palaeomonsoon variations during the Late Holocene. The palaeovegetation was reconstructed using the carbon isotopic composition of bulk organic matter (δ13Corg) and organic geochemical proxies (C/N ratio, Corg %, N % and CaCO3). The vegetation composition (C3 and C4 plants) in the Pookot Lake catchment has changed in response to monsoonal variations. Around 2500 cal. years B.P., the lake had a high water level, increased aquatic plankton activity and abundant C3 vegetation in its catchment, indicating strong monsoonal conditions. From 2500 to 1000 cal. years B.P., the lake had a lower water level, decreased aquatic plankton activity and increased contribution from C4 land plants, indicating low rainfall conditions. During 1500 to 1000 cal. years B.P., the contributions from C3 land plants and aquatic plankton increased, suggesting a moderate rainfall. From 1000 cal. years B.P. to the Present, the abundances of C3 and C4 vegetation fluctuated, indicating variations in the monsoonal strength. During the Medieval Warm Period (1000 to 600 cal. years B.P.), the monsoon was strong, but it was weak during the Little Ice Age (600 to 350 cal. years B.P.). From 350 cal. years B.P. to the Present, it has been steady. A similar climatic trend is documented in other palaeovegetation records from geographically different parts of India although spatial variability exists. Archaeological lines of evidence suggest a possible climate–culture link in the region.

Genome and time-of-day transcriptome of Wolffia australiana link morphological extreme minimization with un-gated plant growth

Abstract: Wolffia is the fastest growing plant genus on Earth with a recorded doubling time of less than a day. Wolffia has a dramatically reduced body plan, primarily growing through a continuous, budding-type asexual reproduction with no obvious phase transition. Most plants are bound by the 24-hour light-dark cycle with the majority of processes such as gene expression partitioned or phased to a specific time-of-day (TOD). However, the role that TOD information and the circadian clock plays in facilitating the growth of a fast-growing plant is unknown. Here we generated draft reference genomes for Wolffia australiana (Benth.) Hartog & Plas to monitor gene expression over a two-day time course under light-dark cycles. Wolffia australiana has the smallest genome size in the genus at 357 Mb and has a dramatically reduced gene set at 15,312 with a specific loss of root (WOX5), vascular (CASP), circadian (TOC1), and light-signaling (NPH3) genes. Remarkably, it has also lost all but one of the NLR genes that are known to be involved in innate immunity. In addition, only 13% of its genes cycle, which is far less than in other plants, with an overrepresentation of genes associated with carbon processing and chloroplast-related functions. Despite having a focused set of cycling genes, TOD cis-elements are conserved in W. australiana, consistent with the overall conservation of transcriptional networks. In contrast to the model plants Arabidopsis thaliana and Oryza sativa, the reduction in cycling genes correlates with fewer pathways under TOD control in Wolffia, which could reflect a release of functional gating. Since TOD networks and the circadian clock work to gate activities to specific times of day, this minimization of regulation may enable Wolffia to grow continuously with optimal economy. Wolffia is an ideal model to study the transcriptional control of growth and the findings presented here could serve as a template for plant improvement.

Potentiality of Wild Rice in Quality Improvement of Cultivated Rice Varieties

Abstract: Rice serves as a major food crop to the majority of the world’s population. O. rufipogan and O. nivara are the two common wild varieties of rice found in Asia. O. sativa and O. glaberrina are two of the cultivated varieties of rice found in Asia. O. rufipogan has disease resistance and drought tolerance. Domestication of rice started when people thought to cultivate rice in different geographical regions to where they migrated. The cultivated rice varieties started to adapt to new climatic and environmental conditions in which they are cultivated, resulting in domesticated varieties of rice. Genetic diversity of rice is exploited to breed new varieties of rice. Rice blast, a disease caused by Xanthomonas oryzae in rice, can be controlled by breeding disease-resistant varieties through the exploitation of genetic diversity. Techniques like molecular markers and other next-generation sequencing technologies have been used to identify the genetic variation among different varieties of rice. For broadening the gene pool of the rice varieties, a technique known as wild hybridization has been widely used. It involves the hybridization of rice with related species of wild varieties. Marker-assisted selection method of breeding increases the efficiency of breeding rather than conventional methods. Marker-assisted pyramiding involves combining many genes together to form one genotype. This method is useful in providing pest resistance and tolerance to abiotic stress. Gene introgression involves the movement of alleles of a species to the gene pool of other species. Gene introgression can result in plant evolution because it introduces variations among genes for the plant to adapt changes in the environment. Nevertheless, gene introgression provides short-term genetic diversity; the original genetic diversity of rice species is usually lost.

Isopropylation of 2-naphthol over mesoporous silicoaluminophosphate-37 (MESO-SAPO-37): the effect of bond dissociation energy on product distribution

Abstract: The vapor phase isopropylation of 2-naphthol (2-NP) with isopropyl alcohol (IPA) in the presence of recently developed mesoporous silicoaluminophosphate assembled from a microporous SAPO-37 precursor (MESO-SAPO-37) was investigated. The bond dissociation energy calculation revealed that the reaction proceeds by O-alkylation followed by rearrangment into C-alkylated products. The presence of a phenolic hydroxyl group facilitates o- and p-directing (1- and 6-positions of 2-NP) and favors 1- and 6-isopropyl-2-naphthols as the major products. The moderately acidic MESO-SAPO-37 showed a maximum 2-NP conversion of 60% achieved with a selectivity of 60% for 6-isopropyl-2-naphthol (6-IP-2-NP) under optimum reaction conditions (T = 250 °C, WHSV = 9.4 h−1 and a 2-NP : IPA ratio of 1 : 20).

Defensive Role of Plant Phenolics Against Pathogenic Microbes for Sustainable Agriculture

Abstract: Plant phenolics are secondary metabolites of plants which have different functions in plantlike giving color and odor to the fruit and flower, defense against biotic and abiotic stresses. Studies in the field of utilization of plant phenolics are scanty. The plant microbe pathogens include bacteria, fungi, and viruses caused a lot of economical loss in agricultural field. The reduced output, rising prices and side effects of chemical pesticides are pushing the farmers to find an alternative. Plant phenols which act as an innate defensive mechanism in many plants against plant micro pathogens can be standardized and used as pesticides. Biological pesticides made of plant phenolics can effectively replace the chemical pesticides. This review says about the general defensive properties of plant phenolics, studies on the defensive role of plant phenolics in both intact plants, and effect of extracted phenolics in crop plants. The review also suggests more studies in the field of defensive utility of plant phenolics.