NMR metabolite profiling analysis of pigmented rice resistance to rice ear bug

Rice ear bugs or Leptocorisa oratorius F. are major rice pests reported to reduce the rice yields severely. The present study aimed to screen local pigmented cultivars for resistance to rice ear bugs and perform metabolomics analysis to identify the metabolites responsible for the resistance character. For screening, eight cultivars including both black and red varieties were used. Rice ear bugs used for bioassay were collected from the field. The assay results showed that two cultivars of black rice and one cultivar of red rice exhibited high resistance characters as per the Standard Evaluation System guidelines for rice. Metabolite profiling of rice seeds was performed at the milky stage using 500 Mhz NMR JEOL, followed by multivariate analysis with SIMCA ver 14. Metabolite profiling identified nine out of 15 metabolites, which were significantly different between the most resistant and susceptible cultivars. In the red rice, hydroxy-L-proline, threonine and formic acid and for black rice, valine, glutamate, α-glucose, β-glucose, galactinol and raffinose were identified as potential metabolites conferring the resistance character. This study identified the most resistant cultivars which can be used in the future to support the development of a novel line of cultivar resistant to rice ear bug. © 2021 World Research Association. All rights reserved

Identification of early flowering mutant gene in Phalaenopsis amabilis (L.) Blume for sgRNA construction in CRISPR/Cas9 genome editing system

Phalaenopsis amabilis (L.) Blume commonly called Moth Orchid (Orchidaceae) is a natural orchid species designated as the National Flower of Indonesia for its beautiful flower shape and long-lasting flowering period. Basically, P. amabilis has a long vegetative phase that cause late flowering, about 2 to 3 years for flowering, hence a method to shorten vegetative period is desired. The latest technological approach that can be used to accelerate flowering of P. amabilis is the CRISPR/Cas9 genome editing method to inactivate the GAI (Gibberellic Acid Insensitive) gene as a mutant gene that can accelerate the regulation of FLOWERING TIME (FT) genes flowering biosynthesis pathway. The approach that needs to be taken is to silence the GAI gene with a knockout system which begins with identifying and characterizing the GAI target gene in the P. amabilis which will be used as a single guide RNA. CRISPR/Cas9 mediated knockout efficiency is highly dependent on the properties of the sgRNA used. SgRNA consists of a target sequence, determining its specificity performance. We executed phylogenetic clustering for the PaGAI protein with closely related orchid species such as Dendrobium capra, Dendrobium cultivars and Cymbidium sinensis. SWISS-Model as tool webserver for protein structure homology modeling. Results show that P. amabilis has a specific domain with the occurrence of point mutations in the two conservative domains. Therefore, a single guide RNA reconstruction needs to be implemented. © 2024, Instituto Internacional de Ecologia. All rights reserved