Fig 1 - uploaded by Zhaohui Chu
Content may be subject to copyright.
OsHsp18.0-CI is induced by Xoc inoculation. The expression level of OsHsp18.0-CI in response to RS105 in Shengdao806 at 0, 6, 12, 24 and 72 h post inoculation. The bars represent the means (three replicates for gene expression) ± SD. The significance of expression compared to 0 h at P values of less than 0.05 and 0.01 are marked by " * " and " ** " , respectively
Source publication
Background
The small heat shock proteins represent a large family of proteins that respond to a wide range of abiotic and biotic stresses. OsHsp18.0-CI confers tolerance to salt and cadmium and interacts with viral RNA-dependent RNA polymerase (RdRp). However, the direct function of OsHsp18.0-CI in resistance against biotic stresses remains unclear...
Contexts in source publication
Context 1
... by M. grisea and rice viruses ( Sarkar et al. 2009;Li et al. 2015), we determined if it is also induced by Xoc. We measured the expression of OsHsp18.0-CI post- inoculation with the Xoc strain RS105 in the suscep- tible rice variety Shengdao 806. The transcript level of OsHsp18.0-CI increased quickly after 6 h post- inoculation (hpi) with RS105 ( Fig. 1) and reached maximum level at 24 hpi, with an increase of 16-fold compared with the control. Expression then decreased to nearly the same level as the control at 72 hpi. This result suggests that the expression of OsHsp18.0-CI is induced by Xoc, as observed for previously reported defense-related genes (Feng et al. 2016). ...
Context 2
... with non-infected WT (WT), a total of 403 up-regulated genes and 72 down-regulated genes were detected in non-infected CD39R (OE, Fig. 5a and b, Additional file 2: Table S2). GO functional annotation of the DEGs in- dicated that the up-and down-regulated genes could be classified into 28 categories, as shown in Additional file 3: Figure S1, such as response to endogenous stimulus, signal transduction, cellular process, response to abiotic stimulus, response to stress, and response to biotic stimulus. The progeny of two T 1 lines (CD40R-9 and CD40R-12) showed significant reductions in lesion length after inoculation with Xoc. ...
Context 3
... of the expression of OsHsp18.0-CI by the fungus M. grisea and at least seven rice viruses has previously been reported ( Sarkar et al. 2009;Li et al. 2015). In the present study, the expression of OsHsp18.0-CI was activated by inoculation with a strain of Xoc, a bacterial pathogen (Fig. 1). This result indicates that OsHsp18.0-CI belongs to the DR genes, which respond to a broad spectrum of pathogens in rice. Consistent with the up-regulation of expression by Xoc, overexpression of OsHsp18.0-CI increased re- sistance, whereas repression of the expression of OsHsp18.0-CI enhanced susceptibility to Xoc. The ex- pression ...
Citations
... Total RNAs was extracted using an RNeasy plant mini Kit (Qiagen, Hilden, Germany) according to the manufacturer's instructions. As previously reported (Ju et al., 2017), six libraries were constructed and sequenced by the Beijing Genomics Institute (www.genomics.org.cn BGI, Shenzhen, China). ...
Bacillus pumilus TUAT1 acts as plant growth-promoting rhizobacteria (PGPR) for various plants like rice and Arabidopsis. Under stress conditions, B. pumilus TUAT1 forms spores with a thick peptidoglycan (PGN) cell wall. Previous research showed that spores were significantly more effective than vegetative cells in enhancing plant growth. In Arabidopsis, the lysin-motif proteins LYM1, LYM3, and CERK1 are required for recognizing bacterial peptidoglycans (PGNs) to mediate immunity. Here, we examined the involvement of PGN receptor proteins in the PGP effects of B. pumilus TUAT1 using Arabidopsis mutants defective in PGNs receptors. Root growth of wild-type, cerk1-1, lym1-1 and lym1-2 mutant plants was significantly increased by TUAT1 inoculation, but this was not the case for lym3-1 and lym3-2 mutant plants. RNA-seq analysis revealed that the expression of a number of defense-related genes was upregulated in lym3 mutant plants. These results suggested that B. pumilus TUAT1 may act to reduce the defense response, which is dependent on a functional LYM3. The expression of the defense-responsive gene, WRKY29, was significantly induced by the elicitor flg-22, both in wild-type and lym3 mutant plants, while this induction was significantly reduced by treatment with B. pumilus TUAT1 and PGNs in wild-type, but not in lym3 mutant plants. These findings suggest that the PGNs of B. pumilus TUAT1 may be recognized by the LYM3 receptor protein, suppressing the defense response, which results in plant growth promotion in a trade-off between defense and growth.
... Moreover, the constitutive expression of OsMPK6 [46], OsGH3-2 [47], OsPGIP4 [48], OsHSP18.0-CI [49], OsMAPK10.2 [50], OsPSKR1 [51], OsPGIP1 [52], OsHSFB4d [53], OsPDX1.2 ...
Downy Mildew Resistance 6-like (DMR6-like) genes are identified as salicylic acid (SA) hydroxylases and negative regulators of plant immunity. Previously, we identified two rice DMR6-like genes, OsF3H03g, and OsF3H04g, that act as susceptible targets of transcription activator-like effectors (TALEs) from Xanthomonas oryzae pv. oryzicola (Xoc), which causes bacterial leaf streak (BLS) in rice. Furthermore, all four homologs of rice DMR6-like proteins were identified to predominantly carry the enzyme activity of SA 5-hydroxylase (S5H), negatively regulate rice broad-spectrum resistance, and cause the loss of function of these OsDMR6s, leading to increased resistance to rice blast and bacterial blight (BB). Here, we curiously found that an OsF3H04g knock-out mutant created by T-DNA insertion, osf3h04g, was remarkedly susceptible to BLS and BB and showed an extreme reduction in SA content. OsF3H04g knock-out rice lines produced by gene-editing were mildly susceptible to BLS and reduced content of SA. To explore the susceptibility mechanism in OsF3H04g loss-of-function rice lines, transcriptome sequencing revealed that another homolog, OsS3H, had induced expression in the loss-of-function OsF3H04g rice lines. Furthermore, we confirmed that a great induction of OsS3H downstream and genomically adjacent to OsF3H04g in osf3h04g was primarily related to the inserted T-DNA carrying quadruple enhancer elements of 35S, while a slight induction was caused by an unknown mechanism in gene-editing lines. Then, we found that the overexpression of OsS3H increased rice susceptibility to BLS, while gene-editing mediated the loss-of-function OsS3H enhanced rice resistance to BLS. However, the knock-out of both OsF3H04g and OsS3H by gene-editing only neutralized rice resistance to BLS. Thus, we concluded that the knock-out of OsF3H04g activated the expression of the OsS3H, partially participating in the susceptibility to BLS in rice.
... Efforts to develop BLS-resistant rice varieties necessitated the exploration and utilization of genes associated with RBLS. To date, several genes related to bacterial leaf streak disease in rice have been cloned [31,32,[35][36][37][38]. The CRISPR/Cas9 system was used to edit the promoter region of the BLS susceptibility gene OsSULRT3;6, which effectively enhanced the resistance of rice to BLS [35]. ...
... Compared with the wild-type, overexpression (OE) lines of OsHsp18.0-CI showed enhanced resistance to RS105, whereas repression lines showed compromised resistance to RS105 [37]. Compared to wild-type controls, transgenic rice plants overexpressing DEPG1 exhibited enhanced susceptibility to Xoc [39]. ...
... In our QTL analysis using FarmCPU, we detected previously identified RBLS genes OsPSKR1 and Osaba1. However, many genes previously identified using mutants and gene differential expression as related to BLS resistance [31,32,[35][36][37][38] did not exhibit mutations or variations in our populations. As a result, it may be necessary to investigate additional populations to identify distinct functional genes. ...
Background
Rice is the second-largest food crop in the world and vulnerable to bacterial leaf streak disease. A thorough comprehension of the genetic foundation of agronomic traits was essential for effective implementation of molecular marker-assisted selection.
Results
Our study aimed to evaluate the vulnerability of rice to bacterial leaf streak disease (BLS) induced by the gram-negative bacterium Xanthomonas oryzae pv. oryzicola (Xoc). In order to accomplish this, we first analyzed the population structure of 747 accessions and subsequently assessed their phenotypes 20 days after inoculation with a strain of Xoc, GX01. We conducted genome-wide association studies (GWAS) on a population of 747 rice accessions, consisting of both indica and japonica subpopulations, utilizing phenotypic data on resistance to bacterial leaf streak (RBLS) and sequence data. We identified a total of 20 QTLs associated with RBLS in our analysis. Through the integration of linkage mapping, sequence analysis, haplotype analysis, and transcriptome analysis, we were able to identify five potential candidate genes (OsRBLS1—OsRBLS5) that possess the potential to regulate RBLS in rice. In order to gain a more comprehensive understanding of the genetic mechanism behind resistance to bacterial leaf streak, we conducted tests on these genes in both the indica and japonica subpopulations, ultimately identifying superior haplotypes that suggest the potential utilization of these genes in breeding disease-resistant rice varieties.
Conclusions
The findings of our study broaden our comprehension of the genetic mechanisms underlying RBLS in rice and offer significant insights that can be applied towards genetic improvement and breeding of disease-resistant rice in rapidly evolving environmental conditions.
... conferred chaperone activity to protect denatured proteins, and OsHsp18.0 was induced by ROS-generating chemicals (Guan, et al. 2004). Few reports on the functional role of sHSPs has been associated with conferring tolerance to abiotic and biotic stress tolerance (Ju, et al. 2017;Wang, et al. 2015). For instance, OsHsp18.0-CI ...
... For instance, OsHsp18.0-CI enhanced resistance against bacterial pathogenic Xoc, salt, cadmium and viral RdRp (Ju, et al. 2017). Moreover, this study shows that OsHsp18.0-CI ...
Plants synthesis multiple families of sHSPs with monomer sizes ranging from 12 to 42 kDa, are the most diverse and more abundant than in other organisms (Wu et al., 2022). In addition to heat tolerance, the sHSPs suggesting that they may play important roles other cellular processes under normal conditions (Wu et al., 2022). Over the past decades, it has been observed that the expression of certain plant sHSPs is induced by a range of stressors, including heat, salt, drought, osmotic, hormonal, heavy metal, oxidative stresses, as well as developmental signals specific to plants (Wu, et al. 2022). In addition, a multitude of investigation have involved the overexpression of various sHSPs in both homologous and heterologous plant systems, including E . coli and Yeast models (Santhanagopalan, et al. 2015; Waters and Vierling 2020). The outcomes of many of these experiments have revealed that stress protection conferred by these proteins is restricted to specific conditions and narrow range of plant growth stages. On contrast, suppression of CI or CII sHSPs in A. thaliana by RNAi showed that these sHSPs were required for recovery from a severe heat stress (10 h at 45°C) and have independent functions (McLoughlin, et al. 2016; Wu, et al. 2022). However, additional investigations are needed to uncover further applications for these proteins.
... Bacterial leaf streak (BLS) caused by Xanthomonas oryzae pv. Oryzicola (Xoc) has become a great matter of concern, resulting in 8-32% yield reduction losses all over China [5]. The disease is characterized by the development of discrete, yellowish, translucent, water-soaked lesions on the leaf surface between the veins [6]. ...
... We found that the gene FE36_09860 encodes the TetR_N domain in a subfamily of TetR transcriptional regulators ( Fig. 1 and S1). We knocked out the FE36_09860 gene from the wild-type Xoc YM15, revealing that TetR transcriptional regulator significantly influenced the biofilm formation, ROS production, growth rate, and virulence but had no impact on extracellular polysaccharides (EPS) production and protease activities of Xoc (Figs. [2][3][4][5]. ...
Bacterial leaf streak disease caused by Xanthomonas oryzae pv. Oryzicola (Xoc) is a serious threat to rice production worldwide. Like most bacterial phytopathogens, Xoc also contains multiple regulators involved in the complex regulatory networks to ensure its virulence. In this study, we found two genes, FE36_09860 and
FE36_06255, through quantitative fluorescence PCR essential for Xoc virulence and might be regulated by the diffusible signal factor (DSF) and the global regulator (Clp). We evaluated the characteristics of the TetR family (FE36_09860) and Fur family (FE36_06255) transcriptional regulator genes in in-vitro and in-vivo experiments. Results demonstrated that the deletion of two transcriptional regulators genes, FE36_09860 and FE36_06255,
reduced the virulence of Xoc. Further analysis revealed that the deletion of the FE36_06255 gene results in decreased EPS production, elevated biofilm formation and reactive oxygen species production, and maintained the growth rate of Xoc YM15. In contrast, the deletion of FE36_09860 showed an opposite trend. It is concluded that, as transcriptional regulators, the FE36_09860 and FE36_06255 genes played an important role in the biological processes of Xoc YM15 and were essential for its virulence.
... [13], OsPSKR1 [14], OsHSP18.0-CI [15] and GH3-2 [16]. The BLS resistance of rice was improved by inhibiting the expression of some DR genes, such as OsWRKY45-1 [17], OsDEPG1 [18], OsNRRB [19] and OsMPK6 [20]. ...
Bacterial leaf streak (BLS) caused by Xanthomonas oryzae pv. oryzicola (Xoc) is one of the most important quarantine diseases in the world. Breeding disease-resistant varieties can solve the problem of prevention and treatment of BLS from the source. The discovery of the molecular mechanism of resistance is an important driving force for breeding resistant varieties. In this study, a BLS-resistant near isogenic line NIL-bls2 was used as the material. Guangxi Xoc strain gx01 (abbreviated as WT) and its mutant strain (abbreviated as MT) with a knockout type III effectors (T3Es) gene were used to infect rice material NIL-bls2. The molecular interaction mechanism of rice resist near isogenic lines in response to infection by different pathogenic strains was analyzed by transcriptome sequencing. The results showed that there were 415, 134 and 150 differentially expressed genes (DEGs) between the WT group and the MT group at 12, 24 and 48 h of post inoculation (hpi). Through GO and KEGG enrichment analysis, it was found that, compared with non-pathogenic strains, the T3Es secreted by pathogenic strains inhibited the signal transduction pathway mediated by ethylene (ET), jasmonic acid (JA) and salicylic acid (SA), and the MAPKK (MAPK kinase) and MAPKKK (MAPK kinase kinase) in the MAPK (mitogen-activated protein kinase) cascade reaction, which prevented plants from sensing extracellular stimuli in time and starting the intracellular immune defense mechanism; and inhibited the synthesis of lignin and diterpenoid phytochemicals to prevent plants from establishing their own physical barriers to resist the invasion of pathogenic bacteria. The inhibitory effect was the strongest at 12 h, and gradually weakened at 24 h and 48 h. To cope with the invasion of pathogenic bacteria, rice NIL-bls2 material can promote wound healing by promoting the synthesis of traumatic acid at 12 h; at 24 h, hydrogen peroxide was degraded by dioxygenase, which reduced and eliminated the attack of reactive oxygen species on plant membrane lipids; and at 48 h, rice NIL-bls2 material can resist the invasion of pathogenic bacteria by promoting the synthesis of lignin, disease-resistant proteins, monoterpene antibacterial substances, indole alkaloids and other substances. Through transcriptome sequencing analysis, the molecular interaction mechanism of rice resistance near isogenic lines in response to infection by different pathogenic strains was expounded, and 5 genes, Os01g0719300, Os02g0513100, Os03g0122300, Os04g0301500, and Os10g0575100 closely related to BLS, were screened. Our work provides new data resources and a theoretical basis for exploring the infection mechanism of Xoc strain gx01 and the resistance mechanism of resistance gene bls2.
... However, there are various reports are shown where some of the target gene over expression or silencing help to minimize the BLS disease progression and give protection to the plant as biotic stress tolerance feature. Ju et al. (2017) represented the role of small heat shock protein (HSP) (OsHsp18.0-CI) for protection against BLS in rice. ...
... They have concluded the outcome for the role of OsHsp18.0-CI that not only able to give resistance to the rice plant against BLS but also there is no negative effect of the overexpression of OsHsp18.0-CI in prospect of plant height, grain weight (100 grain), grain thickness and grain width without any significant differences have been observed for tiller number/ plant, grain length and number of grain per panicle in comparison to Shengdao 806 rice cultivar to confirm any negative effect due to OsHsp18.0-CI overexpression. This is the additional detail in terms of role of hsp against biotic stress (BLS resistance) tolerance reported by Ju et al. (2017) apart from the role of abiotic stress resistance cold, drought, and salt, etc. (Ham et al., 2013;Guan et al., 2004;Sarkar et al., 2009). ...
Rice is widely grown in tropical and subtropical regions and is a staple
food crop specifically in the Asian region. This highly valuable crop is
greatly affected by bacterial and fungal diseases that make a significant loss
in crop yield. Around 70 different diseases widely known, that affect
crop yield, 11 are bacterial-originated diseases. Among these 11 bacterial
diseases, bacterial leaf streak (BLS) disease or black chaff disease caused by
gram-negative bacteria, Xanthomonas oryzicola (Xoc) makes 20–30% yield
loss in rice production. This pathogen often enters in plant systems through
stomata or wounds and multiplies itself in the apoplast of mesophyll tissue
and later develops as water-soaked yellow or orange-brown lesion-symptom
especially on the rice leaves. Xoc generally infects the plants grown in high-temperature and highly humid regions (climatic and subtropical environmental conditions). So far, the infection is widely reported in Africa, Asia, Africa, Australia, Bangladesh, South America, India, and Bangladesh. It has been
reported that the defense response in the plant system against Xoc is a quantitative
feature governed by polygenes. However, to manage the drastic effect
of Xoc pathogen, several strategies and measurements are reported like rice
breeding program via QTL mapping, modification in TAL effector binding
sites, overexpression of heat shock protein (HSP), chitosan-mediated defense
response, chemical derivatives, etc., that become helpful to some extent for
the survival of rice plants without affecting much of crop yield due to BLS
infection in untreated or wild-type rice cultivars.
... Conversely, suppressing this gene increased susceptibility to Xoo and Xoc and decreased free SA levels, suggesting that OsHsp18.0-mediated resistance functions via an SA-dependent signalling pathway (Ju et al., 2017;Kuang et al., 2017). The decreased susceptibility of the transgenic rice lines to Xoo and Xoc was not solely due to increased SA levels but also to increased JA and GA levels ( Table 1; Onohata and Gomi, 2020;Zhang et al., 2020a). ...
Plant pathogens destroy crops and cause severe yield losses, leading to an insufficient food supply to sustain the human population. Apart from relying on natural plant immune systems to combat biological agents or waiting for the appropriate evolutionary steps to occur over time, researchers are currently seeking new breakthrough methods to boost disease resistance in plants through genetic engineering. Here, we summarize the past two decades of research in disease resistance engineering against an assortment of pathogens through modifying the plant immune components (internal and external) with several biotechnological techniques. We also discuss potential strategies and provide perspectives on engineering plant immune systems for enhanced pathogen resistance and plant fitness.
... Overexpression of AtHSP20s could improve the tolerance to salt, oxidation, penetration, and high temperature by enhancing the activity of antioxidant enzymes (Mu et al., 2013;Zhang et al., 2013;Sun et al., 2016;Yang et al., 2020). In rice, the OsHSP18.0 gene could strengthen the resistance to bacterial stripe disease by participating in the basic defense response (Ju et al., 2017). OsHSP17-overexpressing transgenic rice exhibited heat tolerance and UV resistance (Murakami et al., 2004). ...
Cucumber is an important vegetable in China, and its yield and cultivation area are among the largest in the world. Excessive temperatures lead to high-temperature disorder in cucumber. Heat shock protein 20 (HSP20), an essential protein in the process of plant growth and development, is a universal protective protein with stress resistance. HSP20 plays crucial roles in plants under stress. In this study, we characterized the HSP20 gene family in cucumber by studying chromosome location, gene duplication, phylogenetic relationships, gene structure, conserved motifs, protein-protein interaction (PPI) network, and cis-regulatory elements. A total of 30 CsHSP20 genes were identified, distributed across 6 chromosomes, and classified into 11 distinct subgroups based on conserved motif composition, gene structure analyses, and phylogenetic relationships. According to the synteny analysis, cucumber had a closer relationship with Arabidopsis and soybean than with rice and maize. Collinearity analysis revealed that gene duplication, including tandem and segmental duplication, occurred as a result of positive selection and purifying selection. Promoter analysis showed that the putative promoters of CsHSP20 genes contained growth, stress, and hormone cis-elements, which were combined with protein-protein interaction networks to reveal their potential function mechanism. We further analyzed the gene expression of CsHSP20 genes under high stress and found that the majority of the CsHSP20 genes were upregulated, suggesting that these genes played a positive role in the heat stress-mediated pathway at the seedling stage. These results provide comprehensive information on the CsHSP20 gene family in cucumber and lay a solid foundation for elucidating the biological functions of CsHSP20. This study also provides valuable information on the regulation mechanism of the CsHSP20 gene family in the high-temperature resistance of cucumber.
... The wheat bacterial leaf streak resistance genes identified to date are mostly QTLs (Wen et al. 2018;Ramakrishnan et al. 2019), and their major resistance genes have not been identified and cloned. Some rice bacterial leaf streak defence-related (DR) genes have been reported, such as OsWRKY45-2 (Tao et al. 2009), GH3-2 (Fu et al. 2011), OsPGIP4 (Feng et al. 2016), OsPGIP1 , OsHsp18.0-CI (Ju et al. 2017), OsHsfB4d , OsPSKR1 (Yang et al. 2019), DEPG1 (Guo et al. 2012), OsWRKY45-1 (Tao et al. 2009), OsMPK6 (Shen et al. 2010), NRRB (Guo et al. 2014), OsBGLU19 and OsBGLU23 ). In addition, CRISPR/Cas9 gene editing was used to disrupt the Tal2g-recognized effector binding element (EBE) of the susceptibility gene OsSULTR3; 6 in the rice cultivar IRBB10, which increased its resistance to BLS (Xu et al. 2021). ...
Key message
A novel rice resistance gene, Xo2, influencing pathogenesis of the bacterial leaf streak disease, has been identified, and candidate genes for Xo2 in the fine mapping region have been shown to be involved in bacterial leaf streak resistance.
Abstract
Rice (Oryza sativa) bacterial leaf streak, caused by Xanthomonas oryzae pv. oryzicola (Xoc), is one of the most serious rice bacterial diseases. The deployment of host resistance genes is an effective approach for controlling this disease. The cultivar BHADOIA 303 (X455) from Bangladesh is resistant to most of Chinese Xoc races. To identify and map the resistance gene(s) involved in Xoc resistance, we examined the association between phenotypic and genotypic variations in two F2 populations derived from crosses between X455/Jingang 30 and X455/Wushansimiao. The segregation ratios of the F2 progeny were consistent with the action of a single dominant resistance gene, which was designated as Xo2. Based on rice SNP chip (GSR40K) assays of X455, Jingang 30, and resistant and susceptible pools thereof, we mapped Xo2 to the region from 10 Mb to 12.5 Mb on chromosome 2. The target gene was further finely mapped between the markers RM12941 and D6-1 within an approximately 110-kb region. The de novo sequencing and gene annotation of X455 and Jingang 30 revealed nineteen predicted genes within the target region. RNA-seq and expression analysis showed that four candidate genes, including Osa002T0115800, encoding an NLR resistance protein, were distinctly upregulated. Differential sequence and synteny analysis between X455 and Jingang 30 suggested that Osa002T0115800 is likely the functional Xo2 gene. This study lays a foundation for marker-assisted selection resistance breeding against rice bacterial leaf streak and the further cloning of Xo2.
