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The functions of a large number of genes, including gene families with domains of unknown functions (DUF), still remain unclear. In this study, we analyzed four members of OsDUF1664 (OsDUF1664.1-OsDUF1664.4) in rice Nipponbare. By phylogenetic analysis, DUF1664 members in rice and Arabidopsis were classified into three major groups (I, II, III). Under drought conditions, the expression level of OsDUF1664.3 in rice was significantly elevated. Overexpression of OsDUF1664.3 in Escherichia coli led to a significant enhancement of catalase (CAT) and peroxidase (POD) activities, and improved bacterial resistance to drought. The results of this study will provide important information for further study of the function of the OsDUF1664 family in rice.

With the advance of sequencing technology, the number of sequenced genomes has been rapidly increasing. However, the functions of a large number of genes, including gene families with domains of unknown functions (DUF), still remain unclear. In this study, we analysed eight members of OsDUF617 (OsDUF617.1-OsDUF617.8) in rice Nipponbare. By phylogenetic analysis, all these OsDUF617 proteins could be classified into three major groups (I, II, III). We used real-time polymerase chain reaction to examine the expression of all these OsDUF617 members in 15 distinct rice tissues. The expression of these members under various abiotic stress and abscisic acid (ABA) conditions was also examined. Under drought conditions, the expression level of OsDUF617.8 in rice was significantly elevated. Overexpression of OsDUF617.8 in Escherichia coli led to a significant enhancement of catalase (CAT) and peroxidase (POD) activities, and improved bacterial resistance to osmotic stress. The results of this study will provide important information for further study of the function of the OsDUF617 family in rice. Supplemental data for this article is available online at 10.1080/13102818.2021.1934541.

Rice blast is one of the most serious rice diseases. It is caused by Magnaporthe oryzae resulting in rice shortages. Biological control has become a new measure in the control of plant diseases. In this study, we isolated antagonistic bacteria from the traditional Chinese medicinal plant Baizhi (Angelica dahurica) against M. oryzae. Biochemical, physiological and 16S rDNA sequence analysis proved that it was Bacillus amyloliquefaciens and we named the strain Rdx5. The experiment proved that Rdx5 can produce cellulase, protease, indole-3-acetic acid and 1-amino-cyclopropane-1-carboxylate deaminase. The sterilized culture filtrate of Rdx5 had strong antifungal activity after treatment at 100 °C for 30 min. In addition, its antifungal activity did not change in strong acid, neutral and weak alkaline environment. However, under strong alkaline conditions, the antifungal activity decreased significantly. In vitro and in vivo experiments showed that Rdx5 could prevent and treat rice blast, since the prevention group performed better than the treatment group. B. amyloliquefaciens Rdx5 might provide an alternative resource for the biocontrol of rice blast.

Many proteins in public databases are recognized as proteins with domains of unknown function (DUF). DUF1191 is such a protein family that consists of plant proteins with unknown function. In this study, we analyzed the basic information of four OsDUF1191 members (OsDUF1191.1–OsDUF1191.4) in rice Nipponbare. OsDUF1191 family members can be divided into four categories by phylogenetic analysis. In order to find out whether these members have tissue-specific expression preference, we used real-time polymerase chain reaction to examine the expression in 15 distinct rice tissues. We found that OSDUF1191.1 was preferentially expressed in the roots. The expression of the four OsDUF1191 members under various abiotic stress and abscisic acid (ABA) conditions was also examined. The expression of OsDUF1191.4 was significantly (p

Background: WRKY transcription factor (TF) is one of the largest TF families in plants and plays an important role in plant development and stress protection. However, the function of individual WRKY gene in plants are still under investigation. Here, we identified a new member of WRKY TF family, OsWRKY97 , and analyze its role in stress resistance by using a series of transgenic plant lines.Results: OsWRKY97 , which positively regulates drought tolerance in rice. OsWRKY97 was expressed in all examined tissues and could be induced by various abiotic stresses. OsWRKY97 is located in the nucleus. Compared with the wild-type (WT), OsWRKY97 -overexpressing (OE) plants enhanced the tolerance of rice to drought and osmotic stress. In addition, OE plants also showed higher sensitivity to exogenous abscisic acid (ABA). When exposed to drought stress, up-regulation OsWRKY97 increased the accumulation of ABA and reduced water loss. Furthermore, OE plants achieved higher proline content and reduced levels of malondialdehyde (MDA) and reactive oxygen species (ROS). The homeostasis of ROS was maintained via the activity of active oxygen scavenging enzyme, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), activated by OsWRKY97Conclusions: These results indicate that OsWRKY97 plays a crucial role in the response to drought stress and may possess high potential value in improving drought tolerance in rice.

Rice blast is one of the most destructive diseases of rice and is caused by the infection with rice blast fungus, Magnaporthe oryzae. In the present study, we obtained 12 bacterial isolates from Sichuan basin neutral purplish soil. Among them, the strain named ZW-10 showed significant activity against M. oryzae. Morphological and biochemical studies, along with 16S rDNA sequencing analysis, proved that the strain belongs to Bacillus velezensis. The cell-free culture filtrate of ZW-10 inhibited the growth of M. oryzae, suggesting the presence of active enzymes and secondary metabolites. The experimental results showed that ZW-10 produced cellulase, protease, and peroxidase. The temperature experiment indicated that the secondary metabolisms of ZW-10 remained active at high temperature. In addition, this strain had good acidity resistance. As shown in leaf experiments in vitro as well as field trials, the liquid culture and the cell-free culture filtrate of ZW-10 had significant inhibitory effects on rice blast. In conclusion, ZW-10 can be used as a potential biological agent in the control of rice blast.

Rice blast, caused by the fungus Magnaporthe oryzae, is one of the three major diseases affecting rice production and quality; it reduces rice grain yield by nearly 30%. In the early stage of this study, a strain of Bacillus velezensis with strong inhibition of M. oryzae was isolated and named ZW10. In vitro assays indicated prolonged germination time of conidia of M. oryzae treated with the antifungal substances of ZW10, 78% of the conidia could not form appressorium, and the conidial tubes expanded to form vacuolar structure and then shrank. The results of FDA-PI composite dyes showed that the antifungal substances of ZW10 inhibited the normal activity of M. oryzae hyphae that were rarely able to infect the epidermal cells of rice leaf sheath in vivo tests. In addition, rice treated with the antifungal substances of ZW10 showed a variety of defense responses, including activation of defense-related enzymes, increased expression of the salicylic acid pathway genes, and accumulation of hydrogen peroxide (H2O2), which might function directly or indirectly in resistance to pathogen attack. The field experiment with rice blast infection in different periods showed that the antifungal substances of ZW10 had the same control effect as carbendazim. The significant biological control activity of ZW10 and its capacity to stimulate host defenses suggest that this B. velezensis strain has the potential to be developed into a biopesticide for the biocontrol of rice blast.

Biological control as a promising method to combat plant disease has gained public attention in recent years. In the present study, we isolated 12 strains resistant to Magnaporthe oryzae from western Sichuan subalpine soil. Among them, CQ07 exhibited remarkable activity against M. oryzae. The result of 16S rRNA sequence analysis revealed that CQ07 is approximately 99% similar to Bacillus australimaris. The sterilized culture filtrate of CQ07 inhibited the growth of M. oryzae, which motivated us to deduce the influence of CQ07 on the pathogenicity of M. oryzae. As shown by experimentation, sterilized culture filtrate (10 μl/ml) of CQ07 can delay and even suppress the germination of conidia and prevent the formation of appressorium in vitro and in vivo. In addition, by simulative field tests, the spraying of conidia suspension diluted with sterilized culture filtrate of CQ07 reduced infection of rice blast. To better control rice blasts, understanding the infection mechanism of M. oryzae and inhibiting the mechanism of the antagonistic strain is of great importance.

With the advance of sequencing technology, the number of sequenced plant genomes has been rapidly increasing. However, many plant proteins in public databases are recognised as proteins with domains of unknown function (DUF). DUF872 is such a protein family that consists of plant proteins with unknown function. In this study, we analysed three DUF872 members (OsDUF872.1, OsDUF872.1 and OsDUF872.3) in rice Nipponbare with three distinct motifs. Real-time polymerase chain reaction showed that the expression patterns of the three corresponding OsDUF872 protein-encoding genes varied in 15 different rice tissues. The expression of OsDUF872.2 was significantly (P

Biological control is a promising measure in the control of plant disease. In the present study, we isolated 13 endophytic strains from Angelica dahurica. Among them, an endophytic strain which was named GYLH001 exhibited remarkable activity against Magnaporthe oryzae. 16S rRNA sequence analysis, biochemical and physiological proved that it is Bacillus tequilensis. The sterilized culture filtrate of GYLH001 can inhibit the growth of M.oryzae, which suggests the presence of secondary metabolites. Proved by experiment, GYLH001 can produce cellulase, protease, gelatinase, indole-3-acetic acid and 1-amino-cyclopropane-1-carboxylate deaminase. In addition, the temperature experiment showed that secondary metabolites produced by GYLH001 had good thermal stability. They can remain activity even heated at 100°C for 30 min. They also had good acid-resistance in heavily acidic condition. But under alkaline condition, the antifungal effect decreased significantly. By simulative field tests, the spraying of GYLH001 spore solution could prevent and treat rice blast. Through continuous separation and purification of sterilized culture filtrate and identification by mass spectrometry, the molecular weight of an active substance is 364.26. In the control of rice blast, B. tequilensis GYLH001 has potential as a biological control agent in agriculture.