RESUMEN
In plants, race-specific defence against microbial pathogens is facilitated by resistance (R) genes which correspond to specific pathogen avirulence genes. This study reports the cloning of a blackleg R gene from Brassica napus (canola), Rlm9, which encodes a wall-associated kinase-like (WAKL) protein, a newly discovered class of race-specific plant RLK resistance genes. Rlm9 provides race-specific resistance against isolates of Leptosphaeria maculans carrying the corresponding avirulence gene AvrLm5-9, representing only the second WAKL-type R gene described to date. The Rlm9 protein is predicted to be cell membrane-bound and while not conclusive, our work did not indicate direct interaction with AvrLm5-9. Rlm9 forms part of a distinct evolutionary family of RLK proteins in B. napus, and while little is yet known about WAKL function, the Brassica-Leptosphaeria pathosystem may prove to be a model system by which the mechanism of fungal avirulence protein recognition by WAKL-type R genes can be determined.
Asunto(s)
Brassica napus/genética , Resistencia a la Enfermedad/genética , Leptosphaeria/patogenicidad , Enfermedades de las Plantas/inmunología , Proteínas Quinasas/metabolismo , Brassica napus/inmunología , Brassica napus/microbiología , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Quinasas/genética , Especificidad de la Especie , VirulenciaRESUMEN
Plants as sessile organisms face daily environmental challenges and have developed highly nuanced signaling systems to enable suitable growth, development, defense, or stalling responses. Moonlighting proteins have multiple tasks and contribute to cellular signaling cascades where they produce additional variables adding to the complexity or fuzziness of biological systems. Here we examine roles of moonlighting kinases that also generate 3',5'-cyclic guanosine monophosphate (cGMP) in plants. These proteins include receptor like kinases and lipid kinases. Their guanylate cyclase activity potentiates the development of localized cGMP-enriched nanodomains or niches surrounding the kinase and its interactome. These nanodomains contribute to allosteric regulation of kinase and other molecules in the immediate complex directly or indirectly modulating signal cascades. Effects include downregulation of kinase activity, modulation of other members of the protein complexes such as cyclic nucleotide gated channels and potential triggering of cGMP-dependent degradation cascades terminating signaling. The additional layers of information provided by the moonlighting kinases are discussed in terms of how they may be used to provide a layer of fuzziness to effectively modulate cellular signaling cascades.
Asunto(s)
GMP Cíclico/metabolismo , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Proteínas Quinasas/metabolismo , Transducción de Señal , Guanilato Ciclasa/química , Guanilato Ciclasa/metabolismo , Modelos Moleculares , Proteínas de Plantas/química , Plantas/química , Proteínas Quinasas/química , ProteolisisRESUMEN
Oilseed rape (Brassica napus) is an important oil crop distributed worldwide with a broad adaptation to different climate zones. The cultivation of rapeseed is one of the most commercially viable areas in crop production. Altogether 269,093 ha of rapeseed are cultivated in Kazakhstan. However, all rapeseed cultivars and lines cultivated in Kazakhstan on an industrial scale predominantly belong to the foreign breeding system. Therefore, the formation of a diverse genetic pool for breeding new, highly productive cultivars adopted to the environmental conditions of Kazakhstan is the most important goal in country selection programs. In this work, we have developed ethyl methanesulfonate (EMS) doubled haploid mutant lines from plant material of cultivars 'Galant' and 'Kris' to broad diversity of rapeseed in Kazakhstan. The development of mutant lines was performed via embryo callusogenesis or embryo secondary callusogenesis. Mutants were investigated by Brassica90k SNP array, and we were able to locate 24,657 SNPs from 26,256 SNPs filtered by quality control on the genome assembly (Bra_napus_v2.0). Only 18,831 SNPs were assigned to the available annotated genomic features. The most frequent combination of mutations according to reference controls was adenine with guanine (70%), followed by adenine with cytosine (28.8%), and only minor fractions were cytosine with guanine (0.54%) and adenine with thymine (0.59%). We revealed 5606.27 markers for 'Kris' and 4893.01 markers for 'Galant' by mutation occurrence. Most mutation occurrences were occupied by double mutations where progenitors and offspring were homozygous by different alleles, enabling the selection of appropriate genotypes in a short period of time. Regarding the biological impact of mutations, 861 variants were reported as having a low predicted impact, with 1042 as moderate and 121 as high; all others were reported as belonging to non-coding sequences, intergenic regions, and other features with the effect of modifiers. Protein encoding genes, such as wall-associated receptor kinase-like protein 5, TAO1-like disease resistance protein, receptor-like protein 12, and At5g42460-like F-box protein, contained more than two variable positions, with an impact on their biological activities. Nevertheless, the obtained mutant lines were able to survive and reproduce. Mutant lines, which include moderate and high impact mutations in encoding genes, are a perfect pool not only for MAS but also for the investigation of the fundamental basis of protein functions. For the first time, a collection of mutant lines was developed in our country to improve the selection of local rapeseed cultivars.