Cysteine-rich receptor-like kinases (CRKs) took crucial roles in plant cell growth and development, as well as environmental adaption. Apple (
Malus domestica
) had been considered a staple fruit ...crop and a model of woody plants. In this study, the annotation, evolution, and duplication of the CRK gene family members in apple (
MdCRK
) were characterized. Besides, we also investigated the expressional patterns of
MdCRK
s in various tissue types and response to signals from
Alternaria alternate
apple pathotype (
Aa
AP),
Penicillium expansum
(
Pe
), and
Valsa mali
(
Vm
). A total of 36
MdCRK
s were annotated. The phylogenetic analysis of CRKs among apple,
Arabidopsis thaliana
, rice (
Oryza sativa
), cotton (
Gossypium hirsutum
), banana (
Musa acuminata
), and tomato (
Solanum lycopersicum
) revealed the distinct evolutionary characteristics in plants. Based on gene duplication analysis, seven tandem gene clusters containing 24 members and ten segmental gene pairs were found from
MdCRK
s. A large number segmental gene pairs were identified from
CRK
s between apple and cotton. Abscisic acid (ABA) and methyl jasmonate (MeJA)–responsive cis-elements were discovered from the promoter region of most
MdCRK
s.
MdCRK
s showed distinct tissue and developmental expression patterns. Most members displayed distinct expression patterns among various tissue types. Six members were differentially expressed in response to signals from at least two pathogenic fungi. Our study provides valuable information for further studies on the evolution and functional investigation on disease resistance of CRKs.
Key message
In
Rosaceae
, tandem duplication caused the drastic expansion of CNGC gene family Group I. The members
MdCN11
and
MdCN19
negatively regulate
Valsa
canker resistance.
Apple (
Malus ...domestica
) and pear (
Pyrus bretschneideri
and
P. communis
) are important fruit crops in
Rosaceae
family but are suffering from threats of
Valsa
canker. Cyclic nucleotide-gated ion channels (CNGCs) take crucial roles in plant immune responses. In the present study, a total of 355 CNGCs was identified from 8
Rosaceae
plants. Based on phylogenetic analysis, 540 CNGCs from 18 plants (8 in
Rosaceae
and 10 others) could be divided into four groups. Group I was greatly expanded in
Rosaceae
resulted from tandem duplications. A large number of
cis
-acting regulatory elements (
cis
-elements) responsive to signals from multiple stresses and hormones were identified in the promoter regions of CNGCs in
Malus spp.
and
Pyrus spp
. Expressions of most Group I members were obviously up-regulated in
Valsa
canker susceptible varieties but not in the resistant ones. Furthermore, overexpression of the
MdCN11
and
MdCN19
in both apple fruits and ‘Duli’ (
P. betulifolia
) suspension cells compromised
Valsa
canker resistance. Overexpression of
MdCN11
induced expression of hypersensitive response (HR)-related genes. In conclusion, tandem duplication resulted in a drastic expansion of CNGC Group I members in
Rosaceae
. Among these,
MdCN11
and
MdCN19
negatively regulate the
Valsa
canker resistance via inducting HR.
Light is a vital environmental factor that can affect the synthesis of volatile organic compounds (VOCs) in grape berries. However, the mechanism through which light affects the synthesis of VOCs is ...still unclear for wine grapes. In our study, fruit bags with light transmittances of 50%, 15%, 5%, and 0% were used to bag the ‘Marselan’ clusters 45 days after flowering, and these treatments were named A, B, C, and D, respectively. The non-bagged clusters were used as controls (CK). The types and contents of VOCs were determined using a gas chromatography–mass spectrometer (GC–MS) with the berries 35 days before harvest (S1), 25 days before harvest (S2), and at the harvest stage (S3). RNA-seq analysis was performed on S2 and S3 samples. The results showed that the types and total contents of VOCs synthesized by fatty acid metabolic and isoprene metabolic pathways decreased with a decrease in light intensity in berries at S3. The types of VOCs synthesized by the amino acid metabolic pathway were reduced under complete shading conditions, which was consistent with results of other treatments and in the CK. The total content of VOCs was significantly reduced in shaded berries. The components of VOCs were also significantly decreased in shaded berries, except for 2-heptanol, cis-7-decenal, and trans-2-hexenal. Furthermore, RNA-seq analysis revealed that the pathway related to VOC synthesis was the alpha-linolenic acid metabolic pathway, which contained 10 differentially expressed genes from the
LOXO
,
HPL
, and
ADH
gene families. Correlation analysis between metabolites and differentially expressed genes of this pathway showed that the synthesis of most VOCs was highly correlated with the expression levels of
LOXOs
(VIT_09s0002g01080, VIT_06s0004g01450),
HPL
(VIT_12s0059g01060), and
ADHs
(VIT_04s0044g01110, VIT_18s0001g15450, VIT_18s0001g15410) (
r
> 0.95,
p
< 0.5) in the fatty acid metabolic pathway. The content of 2-heptanol, cis-7-decenal, and trans-2-hexenal was highly positively correlated with the expression levels of
LOXO
(VIT_13s0064g01480) and
ADH
(VIT_18s0001g15410) (
r
> 0.95,
p
< 0.5). In conclusion, the types and contents of VOCs synthesized by fatty acid metabolic, amino acid metabolic, and isoprene metabolic pathways are reduced in harvested clusters that had been shaded, except for 2-heptanol, cis-7-decenal, and trans-2-hexenal. In addition, the development of VOCs was mainly related to the expressions of
LOXO
,
HPL,
and
ADH
in the fatty acid metabolic pathway.
Valsa
canker is a destructive fungal disease that results in a serious loss of production. The pathogen
Valsa pyri
(
Vp
) usually infiltrates the bark and xylem via the wound. ‘Duli’ (
Pyrus ...betulifolia
), a rootstock with high tolerance to this disease and multiple other stresses, is widely planted in northern China. We found that wound healing plays a crucial role in the resistance of ‘Duli’ against
Vp
infection. Nevertheless, elucidation of the molecular mechanism of this process has been largely limited. Using RNA sequencing (RNA-seq), we investigated dynamic gene expression profiles of ‘Duli’ and ‘Zaosu’ (
Pyrus bretschneideri
, susceptible) phloem tissues which 0–3 mm around the wounded site that were cultured for 1, 3, and 7 days after wounding. Quantitative real-time PCR (qRT-PCR) was used to confirm data veracity. After wounding at 1, 3, and 7 days, 4930, 4652, and 6279 differentially expressed genes (DEGs) were found from ‘Duli’, compared to 1641, 1968, and 3347 in ‘Zaosu’, respectively. Functional enrichment analysis revealed that the DEGs associated with “cell wall organization and biogenesis”, “biosynthesis of secondary metabolites” and “cell wall organization. pectin” were enriched both in ‘Duli’ and ‘Zaosu’. Additionally, expressions of DEGs encoding receptor-like kinase (RLK) subfamily Extensin, LRR-III, LRR-IV, LRR-IX, LRR-XI-1, LRR-XII-1, RLCK-IXa and RLCK-V, and transcription factor CRE1, TF, ABF, TGA, and MYC2 were rapidly activated in ‘Duli’, but only a subtle induction in ‘Zaosu’. In conclusion, DEGs related to cell wall thickening are rapidly and continuously induced in ‘Duli’, which plays a positive role in the formation of protective tissues. Notably, JA-, SA-, LRR-, RLCK-, and Extensin-related DEGs probably participated in the regulation of multiple molecular networks and contributed to the quick wound healing of ‘Duli’.
Fusarium wilt of banana, a destructive disease that affects banana production, is caused by
f. sp.
tropical race 4 (
TR4). In a previous study, we confirmed the strong inhibitory effects of Chinese ...leek (
) on the incidence of this disease. Sulfur compounds are the primary antifungal constituents of Chinese leek. Among these, dimethyl trisulfide (DT) was the most abundant and exhibited the strongest inhibition of
TR4 growth and development. In the present study, the global gene expression profiles of
TR4 isolates treated with DT at 4,000-folds dilution (concentration of 1/4,000, v/v) for 1.5, 6, and 12 h were investigated by using RNA sequencing. The expression patterns of 15 DEGs were validated based on quantitative real-time PCR (qRT-PCR) assay. Untreated sample presented 2,556, 1,691, and 1,150 differentially expressed genes (DEGs) at 1.5, 6, and 12 h after the onset of the experiment, respectively, whereas DT-treated isolates presented 2,823, 3,546, and 6,197 DEGs. Based on Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, DEGs involved in endoplasmic reticulum (ER), glycosylation, and steroid biosynthesis were significantly inhibited by DT exposure. The similar expressional patterns of 15 DEGs between RNA-seq and qRT-PCR assays indicated the reliability of the RNA-seq data. In conclusion, ER stress related to glycosylation inhibition and damage to cell membrane integrity might contribute to the toxicity of DT against
TR4. As the results presented here evidenced changes in gene expression associated with DT exposure, which might be used to develop new approaches for controlling FWB.
Gibberellin (GAs) plays the important role in the regulation of grape developmental and growth processes. The bioinformatics analysis confirmed the differential expression of GA2, GA3, and GA20 ...gibberellin oxidase genes (
2
,
and
) in the grape genome, and laid a theoretical basis for exploring its role in grape. Based on the Arabidopsis
,
, and
genes already reported, the
,
, and
genes in the grape genome were identified using the BLAST software in the grape genome database. Bioinformatics analysis was performed using software such as DNAMAN v.5.0, Clustalx, MapGene2Chrom, MEME, GSDS v.2.0, ExPASy, DNAsp v.5.0, and MEGA v.7.0. Chip expression profiles were generated using grape Affymetrix GeneChip 16K and Grape eFP Browser gene chip data in PLEXdb. The expression of
,
, and
gene families in stress was examined by qRT-PCR (Quantitative real-time-PCR). There are 24
genes identified with the grape genome that can be classified into seven subgroups based on a phylogenetic tree, gene structures, and conserved Motifs in our research. The gene family has higher codon preference, while selectivity is negative selection of codon bias and selective stress was analyzed. The expression profiles indicated that the most of
genes were highly expressed under different time lengths of ABA (Abscisic Acid) treatment, NaCl, PEG and 5 °C. Tissue expression analysis showed that the expression levels of
and
in different tissues at different developmental stages of grapes were relatively higher than that of
. Last but not least, qRT-PCR (Real-time fluorescent quantitative PCR) was used to determine the relative expression of the
gene family under the treatment of GA3 (gibberellin 3) and uniconazole, which can find that some
was upregulated under GA3 treatment. Simultaneously, some
and
were upregulated under uniconazole treatment. In a nutshell, the
gene mainly functions to inactivate biologically active GAs, while
mainly degrades C20 gibberellins, and
is mainly composed of biologically active GAs. The comprehensive analysis of the three classes of
would provide a basis for understanding the evolution and function of the
gene family in a grape plant.
Fusarium oxysporum
f. sp.
cubense
(
Foc
) is the causal pathogen of Fusarium wilt of banana. To understand infection of banana roots by
Foc
race 4, we developed a green fluorescent protein ...(GFP)-tagged transformant and studied pathogenesis using fluorescence microscopy and confocal laser scanning microscopy. The transformation was efficient, and GFP expression was stable for at least six subcultures with fluorescence clearly visible in both hyphae and spores. The transformed
Foc
isolate also retained its pathogenicity and growth pattern, which was similar to that of the wild type. The study showed that: (i)
Foc
race 4 was capable of invading the epidermal cells of banana roots directly; (ii) potential invasion sites include epidermal cells of root caps and elongation zone, and natural wounds in the lateral root base; (iii) in banana roots, fungal hyphae were able to penetrate cell walls directly to grow inside and outside cells; and (iv) fungal spores were produced in the root system and rhizome. To better understand the interaction between
Foc
race 4 and bananas, nine banana cultivars were inoculated with the GFP-transformed pathogen. Root exudates from these cultivars were collected and their effect on conidia of the GFP-tagged
Foc
race 4 was determined. Our results showed that roots of the
Foc
race 4-susceptible banana plants were well colonized with the pathogen, but not those of the
Foc
race 4-resistant cultivars. Root exudates from highly resistant cultivars inhibited the germination and growth of the Fusarium wilt pathogen; those of moderately resistant cultivars reduced spore germination and hyphal growth, whereas the susceptible cultivars did not affect fungal germination and growth. The results of this work demonstrated that GFP-tagged
Foc
race 4 isolates are an effective tool to study plant–fungus interactions that could potentially be used for evaluating resistance in banana to
Foc
race 4 by means of root colonization studies. Banana root exudates could potentially also be used to identify cultivars in the Chinese Banana Germplasm Collection with resistance to the Fusarium wilt pathogen.
The necrotrophic pathogen
Valsa mali (Vm)
resulting
Valsa
canker of apple is considered one of the most destructing fungal diseases. To study the resistance mechanism, we investigated gene expression ...profiles of suspension cells from resistant varieties ‘Dongbeishanjingzi’ (DS,
Malus baccata
) and susceptible varieties ‘Gala’ (GL,
Malus
×
domestica
) in response to
Vm
metabolism (
Vm
M) using RNA sequencing (RNA-seq). Functional enrichment showed that differentially expressed genes (DEGs) were widely involved in multiple metabolisms or signals, such as “Lipid metabolic process”, “plant hormone signal transduction” and “plant-pathogen interaction”. Further expressional patterns exhibited that induction of genes related to ‘‘xyloglucan biosynthetic process’’ and ‘‘cell wall biogenesis’’ was beneficial for cell wall integrity and tolerance of DS cells. In brassinosteroid signaling, we identified that TCH4 gene
MbTCH4-1
positively regulated
Vm
resistance of ‘Fuji’ fruit, but BSK gene
MdBSK1
negatively regulated the resistance. In contrast, cell death associated with hypersensitive response caused by up-regulation of CNGCs and CDPK genes is an important cause of weakened tolerance in GL cells. Our results provide a new insight direction for the molecular mechanism of apple against
Valsa
canker.
Fusarium wilt, caused by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases of banana. Toxins produced by Foc have been proposed to play an important ...role during the pathogenic process. The objectives of this study were to investigate the contamination of banana with toxins produced by Foc, and to elucidate their role in pathogenesis.
Twenty isolates of Foc representing races 1 and 4 were isolated from diseased bananas in five Chinese provinces. Two toxins were consistently associated with Foc, fusaric acid (FA) and beauvericin (BEA). Cytotoxicity of the two toxins on banana protoplast was determined using the Alamar Blue assay. The virulence of 20 Foc isolates was further tested by inoculating tissue culture banana plantlets, and the contents of toxins determined in banana roots, pseudostems and leaves. Virulence of Foc isolates correlated well with toxin deposition in the host plant. To determine the natural occurrence of the two toxins in banana plants with Fusarium wilt symptoms, samples were collected before harvest from the pseudostems, fruit and leaves from 10 Pisang Awak 'Guangfen #1' and 10 Cavendish 'Brazilian' plants. Fusaric acid and BEA were detected in all the tissues, including the fruits.
The current study provides the first investigation of toxins produced by Foc in banana. The toxins produced by Foc, and their levels of contamination of banana fruits, however, were too low to be of concern to human and animal health. Rather, these toxins appear to contribute to the pathogenicity of the fungus during infection of banana plants.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Steroidal glycoalkaloids (SGAs), which are widely produced by potato, even in other
plants, are a class of potentially toxic compounds, but are beneficial to host resistance. However, changes of the ...other metabolic process along with SGA accumulation are still poorly understood and researched. Based on RNA sequencing (RNA-seq) and bioinformatics analysis, the global gene expression profiles of potato variety Helan 15 (Favorita) was investigated at four-time points during light exposure. The data was further verified by using quantitative Real-time PCR (qRT-PCR). When compared to the control group, 1288, 1592, 1737, and 1870 differentially expressed genes (DEGs) were detected at 6 h, 24 h, 48 h, and 8 d, respectively. The results of both RNAseq and qRT-PCR showed that SGA biosynthetic genes were up-regulated in the potato tuber under light exposure. Functional enrichment analysis revealed that genes related to PS light reaction and Protein degradation were significantly enriched in most time points of light exposure. Additionally, enriched Bins included Receptor kinases, Secondary metabolic process in flavonoids, Abiotic stress, and Biotic stress in the early stage of light exposure, but PS Calvin cycle, RNA regulation of transcription, and UDP glucosyl and glucoronyl transferases in the later stage. Most of the DEGs involved in PS light reaction and Abiotic stress were up-regulated at all four time points, whereas DEGs that participated in biotic stresses were mainly up-regulated at the later stage (48 h and 8 d).
-element prediction and co-expression assay were used to confirm the expressional correlation between genes that are responsible for SGA biosynthesis and disease resistance. In conclusion, the expressions of genes involved in PS light reaction, Abiotic stress, and Biotic stress were obviously aroused during the accumulation of SGAs induced by light exposure. Moreover, an increased defense response might contribute to the potato resistance to the infection by phytopathogenic microorganisms.
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