CRb and PbBa8.1 Synergically Increases Resistant Genes Expression upon Infection of Plasmodiophora brassicae in Brassica napus

PbBa8.1 and CRb are two clubroot-resistant genes that are important for canola breeding in China. Previously, we combined these resistant genes and developed a pyramid-based, homozygous recurrent inbred line (618R), the results of which showed strong resistance to Plasmodiophora brassicae field isolates; however, the genetic mechanisms of resistance were unclear. In the present work, we conducted comparative RNA sequencing (RNA-Seq) analysis between 618R and its parental lines (305R and 409R) in order to uncover the transcriptomic response of the superior defense mechanisms of 618R and to determine how these two different resistant genes coordinate with each other. Here, we elucidated that the number and expression of differentially expressed genes (DEGs) in 618R are significantly higher than in the parental lines, and PbBa8.1 shares more DEGs and plays a dominant role in the pyramided line. The common DEGs among the lines largely exhibit non-additive expression patterns and enrichment in resistance pathways. Among the enriched pathways, plant–pathogen interaction, plant hormone signaling transduction, and secondary metabolites are the key observation. However, the expressions of the salicylic acid (SA) signaling pathway and reactive oxygen species (ROS) appear to be crucial regulatory components in defense response. Our findings provide comprehensive transcriptomic insight into understanding the interactions of resistance gene pyramids in single lines and can facilitate the breeding of improved resistance in Brassica napus.

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Comparative Transcriptome Analysis of Rutabaga (Brassica napus) Cultivars Indicates Activation of Salicylic Acid and Ethylene-Mediated Defenses in Response to Plasmodiophora brassicae

International Journal of Molecular Sciences ◽

10.3390/ijms21218381 ◽

2020 ◽

Vol 21 (21) ◽

pp. 8381

Author(s):

Qinqin Zhou ◽

Leonardo Galindo-González ◽

Victor Manolii ◽

Sheau-Fang Hwang ◽

Stephen E. Strelkov

Keyword(s):

Salicylic Acid ◽

Brassica Napus ◽

Defense Mechanisms ◽

Plasmodiophora Brassicae ◽

Leucine Zippers ◽

Brassica Napus L ◽

Soilborne Disease ◽

Essential Components ◽

Genes Encoding ◽

Respiratory Burst Oxidase

Clubroot, caused by Plasmodiophora brassicae Woronin, is an important soilborne disease of Brassica napus L. and other crucifers. To improve understanding of the mechanisms of resistance and pathogenesis in the clubroot pathosystem, the rutabaga (B. napus subsp. rapifera Metzg) cultivars ‘Wilhelmsburger’ (resistant) and ‘Laurentian’ (susceptible) were inoculated with P. brassicae pathotype 3A and their transcriptomes were analyzed at 7, 14, and 21 days after inoculation (dai) by RNA sequencing (RNA-seq). Thousands of transcripts with significant changes in expression were identified in each host at each time-point in inoculated vs. non-inoculated plants. Molecular responses at 7 and 14 dai supported clear differences in the clubroot response mechanisms of the two genotypes. Both the resistant and the susceptible cultivars activated receptor-like protein (RLP) genes, resistance (R) genes, and genes involved in salicylic acid (SA) signaling as clubroot defense mechanisms. In addition, genes related to calcium signaling and genes encoding leucine-rich repeat (LRR) receptor kinases, the respiratory burst oxidase homolog (RBOH) protein, and transcription factors such as WRKYs, ethylene responsive factors, and basic leucine zippers (bZIPs), appeared to be upregulated in ‘Wilhelmsburger’ to restrict P. brassicae development. Some of these genes are essential components of molecular defenses, including ethylene (ET) signaling and the oxidative burst. Our study highlights the importance of activation of genes associated with SA- and ET-mediated responses in the resistant cultivar. A set of candidate genes showing contrasting patterns of expression between the resistant and susceptible cultivars was identified and includes potential targets for further study and validation through approaches such as gene editing.

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Two Auxinic Herbicides Affect Brassica napus Plant Hormone Levels and Induce Molecular Changes in Transcription

Biomolecules ◽

10.3390/biom11081153 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1153

Author(s):

Jutta Ludwig-Müller ◽

Roman Rattunde ◽

Sabine Rößler ◽

Katja Liedel ◽

Freia Benade ◽

...

Keyword(s):

Brassica Napus ◽

Expression Patterns ◽

Growth Conditions ◽

Growth Stages ◽

Auxin Response ◽

Time Points ◽

Genes Encoding ◽

Different Temperatures ◽

Indigenous Plant ◽

Over Time

With the introduction of the new auxinic herbicide halauxifen-methyl into the oilseed rape (Brassica napus) market, there is a need to understand how this new molecule interacts with indigenous plant hormones (e.g., IAA) in terms of crop response. The aim of this study was to investigate the molecular background by using different growth conditions under which three different auxinic herbicides were administered. These were halauxifen-methyl (Hal), alone and together with aminopyralid (AP) as well as picloram (Pic). Three different hormone classes were determined, free and conjugated indole-3-acetic acid (IAA), aminocyclopropane carboxylic acid (ACC) as a precursor for ethylene, and abscisic acid (ABA) at two different temperatures and growth stages as well as over time (2–168 h after treatment). At 15 °C growth temperature, the effect was more pronounced than at 9 °C, and generally, the younger leaves independent of the developmental stage showed a larger effect on the alterations of hormones. IAA and ACC showed reproducible alterations after auxinic herbicide treatments over time, while ABA did not. Finally, a transcriptome analysis after treatment with two auxinic herbicides, Hal and Pic, showed different expression patterns. Hal treatment leads to the upregulation of auxin and hormone responses at 48 h and 96 h. Pic treatment induced the hormone/auxin response already after 2 h, and this continued for the other time points. The more detailed analysis of the auxin response in the datasets indicate a role for GH3 genes and genes encoding auxin efflux proteins. The upregulation of the GH3 genes correlates with the increase in conjugated IAA at the same time points and treatments. Also, genes for were found that confirm the upregulation of the ethylene pathway.

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Genome-wide analysis of changes in miRNA and target gene expression reveals key roles in heterosis for Chinese cabbage biomass

Horticulture Research ◽

10.1038/s41438-021-00474-6 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Peirong Li ◽

Tongbing Su ◽

Deshuang Zhang ◽

Weihong Wang ◽

Xiaoyun Xin ◽

...

Keyword(s):

Chinese Cabbage ◽

Leaf Development ◽

Target Genes ◽

Expression Patterns ◽

Seedling Stage ◽

Differentially Expressed ◽

Small Rna Sequencing ◽

Leaf Morphogenesis ◽

Expression Levels ◽

Parental Lines

AbstractHeterosis is a complex phenomenon in which hybrids show better phenotypic characteristics than their parents do. Chinese cabbage (Brassica rapa L. spp. pekinensis) is a popular leafy crop species, hybrids of which are widely used in commercial production; however, the molecular basis of heterosis for biomass of Chinese cabbage is poorly understood. We characterized heterosis in a Chinese cabbage F1 hybrid cultivar and its parental lines from the seedling stage to the heading stage; marked heterosis of leaf weight and biomass yield were observed. Small RNA sequencing revealed 63 and 50 differentially expressed microRNAs (DEMs) at the seedling and early-heading stages, respectively. The expression levels of the majority of miRNA clusters in the F1 hybrid were lower than the mid-parent values (MPVs). Using degradome sequencing, we identified 1,819 miRNA target genes. Gene ontology (GO) analyses demonstrated that the target genes of the MPV-DEMs and low parental expression level dominance (ELD) miRNAs were significantly enriched in leaf morphogenesis, leaf development, and leaf shaping. Transcriptome analysis revealed that the expression levels of photosynthesis and chlorophyll synthesis-related MPV-DEGs (differentially expressed genes) were significantly different in the F1 hybrid compared to the parental lines, resulting in increased photosynthesis capacity and chlorophyll content in the former. Furthermore, expression of genes known to regulate leaf development was also observed at the seedling stage. Arabidopsis plants overexpressing BrGRF4.2 and bra-miR396 presented increased and decreased leaf sizes, respectively. These results provide new insight into the regulation of target genes and miRNA expression patterns in leaf size and heterosis for biomass of B. rapa.

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Mapping of clubroot (Plasmodiophora brassicae) resistance in canola (Brassica napus)

Plant Pathology ◽

10.1111/ppa.12422 ◽

2015 ◽

Vol 65 (3) ◽

pp. 435-440 ◽

Cited By ~ 17

Author(s):

H. Zhang ◽

J. Feng ◽

S.-F. Hwang ◽

S. E. Strelkov ◽

I. Falak ◽

...

Keyword(s):

Brassica Napus ◽

Plasmodiophora Brassicae

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Analysis of Transcriptional Changes in Different Brassica napus Synthetic Allopolyploids

Genes ◽

10.3390/genes12010082 ◽

2021 ◽

Vol 12 (1) ◽

pp. 82

Author(s):

Yunxiao Wei ◽

Guoliang Li ◽

Shujiang Zhang ◽

Shifan Zhang ◽

Hui Zhang ◽

...

Keyword(s):

Gene Expression ◽

Brassica Napus ◽

Differentially Expressed Genes ◽

Expression Patterns ◽

Female Parent ◽

Enrichment Analysis ◽

Differentially Expressed ◽

Transcriptional Changes ◽

Aa Genome ◽

High Degree

Allopolyploidy is an evolutionary and mechanistically intriguing process involving the reconciliation of two or more sets of diverged genomes and regulatory interactions, resulting in new phenotypes. In this study, we explored the gene expression patterns of eight F2 synthetic Brassica napus using RNA sequencing. We found that B. napus allopolyploid formation was accompanied by extensive changes in gene expression. A comparison between F2 and the parent shows a certain proportion of differentially expressed genes (DEG) and activation\silent gene, and the two genomes (female parent (AA)\male parent (CC) genomes) showed significant differences in response to whole-genome duplication (WGD); non-additively expressed genes represented a small portion, while Gene Ontology (GO) enrichment analysis showed that it played an important role in responding to WGD. Besides, genome-wide expression level dominance (ELD) was biased toward the AA genome, and the parental expression pattern of most genes showed a high degree of conservation. Moreover, gene expression showed differences among eight individuals and was consistent with the results of a cluster analysis of traits. Furthermore, the differential expression of waxy synthetic pathways and flowering pathway genes could explain the performance of traits. Collectively, gene expression of the newly formed allopolyploid changed dramatically, and this was different among the selfing offspring, which could be a prominent cause of the trait separation. Our data provide novel insights into the relationship between the expression of differentially expressed genes and trait segregation and provide clues into the evolution of allopolyploids.

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