scholarly journals Use of gene family analysis to discover argonaut (AGO) genes for increasing the resistance of Tibetan hull-less barley to leaf stripe disease

2021 ◽  
Vol 57 (No. 3) ◽  
pp. 226-239
Author(s):  
Xiaohua Yao ◽  
Yue Wang ◽  
Youhua Yao ◽  
Likun An ◽  
Yixiong Bai ◽  
...  

Leaf stripe is a common, but major infectious disease of barley, severely affecting the yield and quality. However, only a few genes have been identified by conventional gene mapping. Gene family analysis has become a fast and efficient strategy for gene discovery. Studies demonstrated that Argonaute (AGO) proteins play an important role in plant disease resistance. Thus, we obtained nine HvAGO genes via mRNA sequencing before and after a Pyrenophora graminea infection of a disease-resistant variety "Kunlun 14" and a susceptible variety "Z1141". We analysed the physicochemical characteristics, gene structures, and motifs of the HvAGO gene sequences and found that these proteins were divided into four clusters by evolutionary distance. There was high consistency in the number of exons, size, and the number and type of motifs in the different clusters. Based on protein phylogenetics, they could be divided into three branches. A collinearity analysis of Tibetan hull-less barley and Arabidopsis thaliana, rice, and maize showed that four genes were collinear with respect to the other three species. The qRT-PCR showed the expression levels of HvAGO1, HvAGO2 and HvAGO4 were significantly increased after infection with Pyrenophora graminea. These three members of the AGO gene family are, thus, speculated to play an important role in barley leaf stripe resistance. The results provide reference for the application of HvAGO genes in the leaf stripe control and the exploration of disease resistance genes in other crops.

2020 ◽  
Author(s):  
Yuexin Li ◽  
Degang Zhao

Abstract Background: Late blight seriously threatens potato cultivation worldwide. The severe and widespread damage caused by the fungal pathogen can lead to drastic decreases in potato yield. Although grafting technology has been widely used to improve crop resistance, the effects of grafting on potato late blight resistance as well as the associated molecular mechanisms remain unclear. Therefore, we performed RNA transcriptome sequencing analysis and the late blight resistance testing of the scion when the potato late blight-resistant variety Qingshu 9 and the susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. The objective of this study was to evaluate the influence of the rootstock on scion disease resistance and to clarify the related molecular mechanisms.Results: A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the expression levels of genes related to plant–pathogen interactions, plant mitogen-activated protein kinase (MAPK) signaling pathways, and plant hormone signal transduction pathways were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. These genes included late blight response genes encoding calcium-dependent protein kinases (CDPKs), chitin elicitor receptor kinases (CERKs), LRR receptor serine/threonine protein kinases (LRR-LRKs), NPR family proteins in the salicylic acid synthesis pathway, and MAPKs. When Favorita was used as the rootstock, the expression levels of the late blight response genes were not up-regulated in the Qingshu 9 scion, but the expression levels of the genes related to proline metabolism, fatty acid chain elongation, and diterpenoid biosynthesis pathways were down-regulated. Resistance results showed that self-grafting of the susceptible variety and grafting with the resistant variety as the rootstock increased the resistance of the susceptible scion to late blight. However, the resistance was stronger after grafting with the resistant variety as the rootstock. Using the susceptible variety as the rootstock decreased the late blight resistance of the resistant scion.Conclusions: Our results showed that changes to the expression of disease resistance genes in the scion after grafting are associated with late blight resistance. The results provide the basis for exploring the molecular mechanism underlying the effects of rootstocks on scion disease resistance.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 434
Author(s):  
Sais-Beul Lee ◽  
Namgyu Kim ◽  
Sumin Jo ◽  
Yeon-Jae Hur ◽  
Ji-Youn Lee ◽  
...  

Bakanae disease is a fungal disease of rice (Oryza sativa L.) caused by the pathogen Gibberella fujikuroi (also known as Fusarium fujikuroi). This study was carried out to identify novel quantitative trait loci (QTLs) from an indica variety Zenith. We performed a QTL mapping using 180 F2:9 recombinant inbred lines (RILs) derived from a cross between the resistant variety, Zenith, and the susceptible variety, Ilpum. A primary QTL study using the genotypes and phenotypes of the RILs indicated that the locus qBK1z conferring bakanae disease resistance from the Zenith was located in a 2.8 Mb region bordered by the two RM (Rice Microsatellite) markers, RM1331 and RM3530 on chromosome 1. The log of odds (LOD) score of qBK1z was 13.43, accounting for 30.9% of the total phenotypic variation. A finer localization of qBK1z was delimited at an approximate 730 kb interval in the physical map between Chr01_1435908 (1.43 Mbp) and RM10116 (2.16 Mbp). Introducing qBK1z or pyramiding with other previously identified QTLs could provide effective genetic control of bakanae disease in rice.


2021 ◽  
Vol 16 (12) ◽  
pp. 125-139
Author(s):  
Gaurav Singh ◽  
Garima Dukariya ◽  
Anil Kumar

The crop plants of the family Leguminosae are second to cereal crops of commercial importance on the basis of area harvested and total production worldwide. It is well known globally that many crops do not give good yield due to certain diseases existing in their plants. Nowadays, there is much emphasis on developing disease resistant varieties of crops and especially of commercial crops. Plants need to protect themselves against attack from viruses, microbes, invertebrates and even other plants. NBS-LRR (Nucleotide binding site-leucine rich repeats) genes belong to the largest plant disease resistance gene family and are responsible for plant resistance to pathogens. Studies of the NBS-LRR gene family in plants represent an intriguing challenge and can provide knowledge on the genomic and molecular mechanisms that form the basis of gene regulation and protein function. Their evolution at the gene and genomic level can be defined through ancient and numerous gene families. In the present study, beneficial concepts for generating basic and fundamental knowledge on the NBS-LRR plant disease resistance genes are discussed with emphasis on selected legume plants of commercial importance.


2020 ◽  
Vol 63 (2) ◽  
pp. 113-118
Author(s):  
M. I. E. Arabi ◽  
M. Jawhar ◽  
E. Al-Shehadah

Barley leaf stripe (BLS) caused by Pyrenophora graminea is an important seed-borne disease of barley causing significant yield and quality losses worldwide. The development of resistant cultivars has proven difficult, therefore, in this work, BLSresistant barley germplasm was developed by crossing six barley cultivars currently used in Europe and West Asia. Out of 270 doubled haploid lines derived from these crosses, 40 lines were evaluated under field artificial infection conditions using incidence (I; proportion of diseased plants) and severity (S; proportion of infected leaf area per plant). Disease resistance parameters showed a broad range of variation in mean I and S values with a continuum of resistance levels ranging from highly susceptible to highly resistant with values being consistently higher in the susceptible ones. However, eight promising resistant lines with high yield per plant were identified. Moreover, BLS severity increased linearly as incidence increased (r = 0.76, P < 0.001). This work suggests that BLS resistance sources identified in this study can be used for further genetic analysis and introgression for varietal improvement, and that the positive correlation between I and S parameters may be beneficial for many types of studies on this disease.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuexin Li ◽  
Degang Zhao

Abstract Background Late blight seriously threatens potato cultivation worldwide. The severe and widespread damage caused by the fungal pathogen can lead to drastic decreases in potato yield. Although grafting technology has been widely used to improve crop resistance, the effects of grafting on potato late blight resistance as well as the associated molecular mechanisms remain unclear. Therefore, we performed RNA transcriptome sequencing analysis and the late blight resistance testing of the scion when the potato late blight-resistant variety Qingshu 9 and the susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. The objective of this study was to evaluate the influence of the rootstock on scion disease resistance and to clarify the related molecular mechanisms. Results A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the expression levels of genes related to plant–pathogen interactions, plant mitogen-activated protein kinase (MAPK) signaling pathways, and plant hormone signal transduction pathways were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. Some of these genes encoded calcium-dependent protein kinases (CDPKs), chitin elicitor receptor kinases (CERKs), LRR receptor serine/threonine protein kinases (LRR-LRKs), NPR family proteins in the salicylic acid synthesis pathway, and MAPKs which were potato late blight response proteins. When Favorita was used as the rootstock, only a few genes of late blight response genes were upregulated in the scion of Qingshu 9. Grafted plants using resistant variety as rootstocks inoculated with P. infestans spores showed significant reductions in lesion size while no significant difference in lesion size was observed when susceptible variety was used as the rootstock. We also showed that this induction of disease resistance in scions, especially scions derived from susceptible potato varieties was mediated by the up-regulation of expression of genes involved in plant disease resistance in scions. Conclusions Our results showed that potato grafting using late blight resistant varieties as rootstocks could render or enhance resistance to late blight in scions derived from susceptible varieties via up-regulating the expression of disease resistant genes in scions. The results provide the basis for exploring the molecular mechanism underlying the effects of rootstocks on scion disease resistance.


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