RESUMEN
Respiration is a major plant physiological process that generates adenosine triphosphate (ATP) to support the various pathways involved in the plant growth and development. After decades of focused research on basic mechanisms of respiration, the processes and major proteins involved in respiration are well elucidated. However, much less is known about the natural variation of respiration. Here we conducted a survey on the natural variation of leaf dark respiration (Rd) in a global rice minicore diversity panel and applied a genome-wide association study (GWAS) in rice (Oryza sativa L.) to determine candidate loci associated with Rd. This rice minicore diversity panel consists of 206 accessions, which were grown under both growth room (GR) and field conditions. We found that Rd shows high single-nucleotide polymorphism (SNP) heritability under GR and it is significantly affected by genotype-environment interactions. Rd also exhibits strong positive correlation to the leaf thickness and chlorophyll content. GWAS results of Rd collected under GR and field show an overlapped genomic region in the chromosome 3 (Chr.3), which contains a lead SNP (3m29440628). There are 12 candidate genes within this region; among them, three genes show significantly higher expression levels in accessions with high Rd. Particularly, we observed that the LRK1 gene, annotated as leucine rich repeat receptor kinase, was up-regulated four times. We further found that a single significantly associated SNPs at the promoter region of LRK1, was strongly correlated with the mean annual temperature of the regions from where minicore accessions were collected. A rice lrk1 mutant shows only ~37% Rd of that of WT and retarded growth following exposure to 35 °C for 30 days, but only 24% reduction in growth was recorded under normal temperature (25 °C). This study demonstrates a substantial natural variation of Rd in rice and that the LRK1 gene can regulate leaf dark respiratory fluxes, especially under high temperature.
Asunto(s)
Genes de Plantas , Oryza/metabolismo , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Proteínas Quinasas/genética , Secuencia de Aminoácidos , Sistemas CRISPR-Cas , Ciclo del Carbono , Dióxido de Carbono/metabolismo , Respiración de la Célula , Clorofila/metabolismo , Ritmo Circadiano/genética , Ritmo Circadiano/fisiología , Oscuridad , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Interacción Gen-Ambiente , Estudio de Asociación del Genoma Completo , Efecto Invernadero , Haplotipos/genética , Calor , Oryza/genética , Oryza/crecimiento & desarrollo , Oryza/efectos de la radiación , Fotosíntesis , Hojas de la Planta/efectos de la radiación , Proteínas de Plantas/fisiología , Polimorfismo de Nucleótido Simple , Proteínas Quinasas/fisiología , Alineación de SecuenciaRESUMEN
In humans, MAPK8IP3 (also known as JIP3) is a neurodevelopmental disorder-associated gene. In Caenorhabditis elegans, the UNC-16 ortholog of the MAPK8IP3 protein can regulate the termination of axon growth. However, its role in this process is not well understood. Here, we report that UNC-16 promotes axon termination through a process that includes the LRK-1 (LRRK-1/LRRK-2) kinase and the WDFY-3 (WDFY3/Alfy) selective autophagy protein. Genetic analysis suggests that UNC-16 promotes axon termination through an interaction between its RH1 domain and the dynein complex. Loss of unc-16 function causes accumulation of late endosomes specifically in the distal axon. Moreover, we observe synergistic interactions between loss of unc-16 function and disruptors of endolysosomal function, indicating that the endolysosomal system promotes axon termination. We also find that the axon termination defects caused by loss of UNC-16 function require the function of a genetic pathway that includes lrk-1 and wdfy-3, 2 genes that have been implicated in autophagy. These observations suggest a model where UNC-16 promotes axon termination by interacting with the endolysosomal system to regulate a pathway that includes LRK-1 and WDFY-3.
Asunto(s)
Axones , Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Endosomas , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Axones/metabolismo , Endosomas/metabolismo , Autofagia , Dineínas/metabolismo , Dineínas/genética , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas Serina-Treonina Quinasas , Proteínas Adaptadoras Transductoras de SeñalesRESUMEN
The nematode Caenorhabditis elegans (C. elegans) is a powerful model organism to systematically analyze the functions of genes of interest in vivo. Especially, C. elegans nervous system is suitable for morphological and functional analyses of neuronal genes due to its optical transparency of the body and the well-established anatomy including neural connections. The C. elegans ortholog of Parkinson's disease-associated gene LRRK2, named lrk-1, has been shown to play a role in the regulation of axonal morphology in a subset of neurons. Here I describe the detailed methodologies for the assessment of LRK-1/LRRK2 function as well as the analysis of genetic interaction involving lrk-1/LRRK2 by performing live imaging of C. elegans mechanosenrory neurons.