Molecular characterisation and structural assessment of an RXLR effector from Phytophthora palmivora, the coconut bud rot pathogen

Phytophthora species are phytopathogenic oomycetes that damage a wide variety of crops. Phytophthora delivers effectors, which are secretory proteins, into the host cells. Effectors promote infection by reprogramming the host cellular machinery and are key determinants of oomycete virulence. The major class of Phytophthora effector proteins contains the RXLR motif. In this study, we have carried out the molecular and structural characterisation of an RXLR effector (RXLR6744) from a virulent P. palmivora isolated from bud rot disease-affected coconut palm. The open reading frame (ORF) of the RXLR6744, amplified using RT-PCR, had a length of 411 bp. The gene was found to encode a predicted protein of 136 amino acids and had a molecular weight of 15.52 kDa. Phylogenetic analysis of the amino acid sequence revealed that it was closely related to RXLR proteins from P. palmivora (causing black pod disease in cocoa) and related species P. megakarya. Topology analysis revealed that the protein was composed of six α-helices. The structural prediction was undertaken by computer-aided homology modelling. From the Ramachandran plot analysis, it could be observed that the majority (96.3%) of amino acids were present in the preferred region, 3.7 per cent of amino acid residues were present in the allowed region, and no residues were observed in the disallowed region. The structure showed an average quality of 94.4 per cent, indicating it to be a high-quality structure. This study provides the detailed characterisation of an RXLR effector from P. palmivora. It will aid the elucidation of its role in pathogenesis and facilitate further refined investigations of the structure/function relationships of oomycete effectors

Sustainability of Farmer Producer Organisations - The case of producer organisations involved in the production and marketing of ‘neera’ in the coconut sector

Neera-the coconut inflorescence sap has been promoted as a potential value-added non-alcoholic beverage with abundant health benefits. The concerted effort of the stakeholder agencies could liberate the product from the policy regulations on its production under the excise act (known as ‘Abkari act’ in Kerala). Subsequently, the coconut producer federations (CPFs) in the State were granted licenses for ‘neera’ production and marketing. However, the majority of the CPFs discontinued the ‘neera’ enterprise, which they have initiated with greater enthusiasm. The present study is a modest attempt to trace the reasons for setbacks experienced in the ‘neera’ sector and also to provide a refined framework for revamping the sector. The details of licenses granted to the CPFs were sourced from the Department of Excise, Government of Kerala. The sample size of the study was 95 (13 CPFs who are still active and 82 CPFs who have discontinued). It was observed that the ‘neera’ value chain is in the evolving stage, and the withdrawal of the institutional support had detrimentally affected the confidence of the CPFs ventured into it. The availability of ‘neera’ technicians (tappers) and the high wage rates have evoked concerns on the profitability as well as the assurance of continuous supply of the product. The study categorically highlights the need for a restructured value chain of ‘neera’ with specific roles assigned to the stakeholders through the creation of functional linkages

Structural and Optical Properties of Electro Sprayed Tin Oxide Thin Films

Semiconducting transparent SnO2 thin films were prepared by microcontroller processed electro spraying technique. The structural and optical properties of the films were studied using X-ray diffractometer, UV-Vis spectrophotometer and Photoluminescence spectroscopy respectively. The polycrystalline nature of the films with tetragonal structure was observed from XRD pattern with the mean grain size of 17 nm. The Optical band gap of the films was calculated from the absorption curve and the interference pattern was observed on transmittance spectra. The calculated band gap of 3.5 eV is larger than the bulk band gap of Tin oxide. The blue emission band at 388 nm was observed from room temperature photoluminescence analysis and the effect of excitation wavelength of the films were studied and discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3598

Characterization of gibberellin 2-oxidase isoforms in coconut (Cocos nucifera L.)

Gibberellins (GAs) are plant hormones that are essential for many developmental processes in plants, including seed germination, stem elongation, leaf expansion, trichome development, pollen maturation and the induction of flowering. Gibberellin 2-oxidase (GA2-ox) regulates plant growth by inactivating endogenous bioactive GAs through 2β-hydroxylation. There is no information about GA2-ox encoding genes or their functions in coconut. In this study, we have identified 10 transcripts encoding different isoforms of GA2-ox from coconut leaf transcriptome data. Sequence comparison and phylogenetic analysis revealed that these 10 transcripts represented different types of GA2-ox. The secondary structure, three dimensional structure and active sites of these 10 isoforms were predicted. Docking studies of different active GAs with these isoforms was also carried out

Studies on genetic relationships and diversity in arecanut (Areca catechu L.) germplasm utilizing RAPD markers

In the present investigation, genetic relationship among 60 arecanut germplasm, consisting of both indigenous and exotic accessions, were assessed using 14 polymorphic RAPD primers. The average polymorphism was 6.64 markers per primer. The PIC values among the 14 primers ranged from 0.19 to 0.49. Similarity values among the accessions ranged between 0.68 and 0.93. Cluster analysis revealed two major clusters. The Indian collections Konkan I, Konkan II and Maidhan formed a separate cluster. All the collections from Indonesia, Sri Lanka, Vietnam, Fiji, Solomon Islands, Singapore and China and some Indian collections (viz., Andaman and Nicobar Islands and North East germplasm collections) formed a second cluster. The clustering pattern was, in general, in accordance with the geographical origin of the collections. The results obtained from this study are crucial for developing effective management strategies for genetic improvement of arecanut

On the identity of Riccia fluitans (Ricciaceae: Marchantiophyta) in India

The status of the species Riccia fluitans in India is discussed in detail. Most of the Indian specimens described under R. fluitans are Riccia stricta. Specimens collected from different parts of India were compared with specimens from BM. Photographs are provided for easy identification

Lejeuneaceae (Marchantiophyta) of the Western Ghats, India

The present study reports 76 species of Lejeuneaceae present in the Western Ghats. Among these three species viz. Archilejeunea abbreviata (Mont.) Vanden Berghen, Otolejeunea semperiana (Gottsche et Steph.) Grolle and Tuyamaella angulistipa (Steph.) Schust. & Kachroo are new to India. One species viz., Lejeunea cocoes Mitt., is a new record for Southern India and three species viz., Archilejeunea minutilobula Udar & U.S.Awasthi, Cololejeunea appressa (A.Evans) Benedix and Cololejeunea udarii G. Asthana & S.C. Srivast. are new records for Kerala. Introduct