scholarly journals Development of rice conidiation media for Ustilaginoidea virens

2019 ◽  
Author(s):  
Yufu Wang ◽  
Fei Wang ◽  
Songlin Xie ◽  
Yi Liu ◽  
Jinsong Qu ◽  
...  

AbstractRice false smut, caused by the ascomycete Ustilaginoidea virens, is a serious disease of rice worldwide. Conidia are very important infectious propagules of U. virens, but the ability of pathogenic isolates to produce conidia frequently decreases in culture, which influences pathogenicity testing. Here, we developed tissue media with rice leaves or panicles that stimulate conidiation of U. virens. Generally, rice leaf media more effectively increased conidiation than panicle media, and certain non-filtered tissue media were better than their filtered counterparts. Among the tested media, the Indica rice leaf medium with 0.06 g/ml of Wanxian 98 leaf was most efficient for inducing conidiation, and it was also usable for conidiation-defective isolates. Although the conidia induced in rice tissue media were smaller, they were able to germinate on potato sucrose agar medium and infect rice normally. This method provides a foundation for the production of conidia in U. virens that will be widely applied in the pathogenicity testing as well as in genetic analyses for false smut resistance in rice cultivars.

2021 ◽  
Author(s):  
Munish Leharwan ◽  
T.V. Arun Kumar

Rice is an important nutritive crop and primary staple food throughout the world. To reach the increasing global grain demand and food security, rice production needs to be monitored and increased. However, abiotic and biotic stresses have impeded rice cultivation both in tropical and sub-tropical regions. Among biotic stressors, false smut of rice incited by fungus Ustilaginoidea virens (Cooke, 1878) is one of the most common and serious disease throughout the rice cultivation areas and cause up to 40% loss in its yield. The disease is hard to stop, because fungus infect the crop during flowering stage and symptoms of the disease are evident after emergence of rice panicle. The fungus completely destroys the grains and converts them into spore balls, which are toxic and unfit for seed production. Further, control of false smut of rice through fungicide application is feasible; however, high usage of fungicides has led to the resistance development in causal agent besides environmental pollution. In this review, we update the most recent progress regarding the pathogen, its distribution, taxonomy, disease cycle and integrated disease management.


Virulence ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1563-1579
Author(s):  
Xiaoyang Chen ◽  
Pingping Li ◽  
Hao Liu ◽  
Xiaolin Chen ◽  
Junbin Huang ◽  
...  

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 546 ◽  
Author(s):  
Truong Minh ◽  
Tran Xuan ◽  
Truong Van ◽  
Yusuf Andriana ◽  
Tran Viet ◽  
...  

Although many investigations on phytochemicals in rice plant parts and root exudates have been conducted, information on the chemical profile of essential oil (EO) and potent biological activities has been limited. In this study, chemical compositions of rice leaf EO and in vitro biological activities were investigated. From 1.5 kg of fresh rice leaves, an amount of 20 mg EO was obtained by distillation and analyzed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization (ESI), and atmospheric pressure chemical ionization (APCI) to reveal the presence of twelve volatile constituents, of which methyl ricinoleate (27.86%) was the principal compound, followed by palmitic acid (17.34%), and linolenic acid (11.16%), while 2-pentadecanone was the least (2.13%). Two phytoalexin momilactones A and B were first time identified in EO using ultra-performance liquid chromatography coupled with electrospray mass spectrometry (UPLC/ESI-MS) (9.80 and 4.93 ng/g fresh weight, respectively), which accounted for 7.35% and 3.70% of the EO, respectively. The assays of DPPH (IC50 = 73.1 µg/mL), ABTS (IC50 = 198.3 µg/mL), FRAP (IC50 = 700.8 µg/mL) and β-carotene oxidation (LPI = 79%) revealed that EO possessed an excellent antioxidant activity. The xanthine oxidase assay indicated that the anti-hyperuricemia potential was in a moderate level (IC50 = 526 µg/mL) as compared with the standard allopurinol. The EO exerted potent inhibition on growth of Raphanus sativus, Lactuca sativa, and two noxious weeds Echinochloa crus-galli, and Bidens pilosa, but in contrast, the growth of rice seedlings was promoted. Among the examined plants, the growth of the E. crus-galli root was the most inhibited, proposing that constituents found in EO may have potential for the control of the problematic paddy weed E. crus-galli. It was found that the EO of rice leaves contained rich phytochemicals, which were potent in antioxidants and gout treatment, as well as weed management. Findings of this study highlighted the potential value of rice leaves, which may provide extra benefits for rice farmers.


2021 ◽  
Vol 22 (8) ◽  
pp. 4069
Author(s):  
Xiaoyang Chen ◽  
Zhangxin Pei ◽  
Pingping Li ◽  
Xiabing Li ◽  
Yuhang Duan ◽  
...  

Rice false smut is a fungal disease distributed worldwide and caused by Ustilaginoidea virens. In this study, we identified a putative ester cyclase (named as UvEC1) as being significantly upregulated during U. virens infection. UvEC1 contained a SnoaL-like polyketide cyclase domain, but the functions of ketone cyclases such as SnoaL in plant fungal pathogens remain unclear. Deletion of UvEC1 caused defects in vegetative growth and conidiation. UvEC1 was also required for response to hyperosmotic and oxidative stresses and for maintenance of cell wall integrity. Importantly, ΔUvEC1 mutants exhibited reduced virulence. We performed a tandem mass tag (TMT)-based quantitative proteomic analysis to identify differentially accumulating proteins (DAPs) between the ΔUvEC1-1 mutant and the wild-type isolate HWD-2. Proteomics data revealed that UvEC1 has a variety of effects on metabolism, protein localization, catalytic activity, binding, toxin biosynthesis and the spliceosome. Taken together, our findings suggest that UvEC1 is critical for the development and virulence of U. virens.


2017 ◽  
Vol 150 (3) ◽  
pp. 669-677 ◽  
Author(s):  
Mingli Yong ◽  
Qide Deng ◽  
Linlin Fan ◽  
Jiankun Miao ◽  
Chaohui Lai ◽  
...  

2015 ◽  
Vol 34 (2) ◽  
pp. 113
Author(s):  
Sudir Sudir ◽  
Dini Yuliani ◽  
Lalu Wirajaswadi

<p>A study was carried out to identify the composition and distribution of Xanthomonas oryzae pv. oryzae (Xoo) pathotypes on rice crop in West Nusa Tenggara, during the 2012 planting season. Three activities were conducted, namely collection of rice leaf samples from the fields, isolation of Xoo from the leaf samples at the laboratory, and testing pathotypes of Xoo at the screen house. Rice leaves showing typical bacterial leaf blight (BLB) symptom were collected from various farmers’ fields. The samples were detached and put into paper envelopes, and were taken to the laboratory for isolation of Xoo, at the Laboratory of Pythopathology of Indonesian Center for Rice Research (ICRR), Sukamandi. Pathotype testing was done in the ICRR screen house by inoculating the leaves of five differential rice varieties using inocula of the Xoo isolates. Resistance of the rice differential varieties was determined based on the BLB disease severity. Inoculated plant with disease severity ≤11% was considered resistant (R) and disease severity &gt;11% was susceptible (S). From the 240 samples of rice leaf infected with BLB collected from West Nusa Tenggara, 232 Xoo isolates were obtained. The Xoo pathotype identification showed that pathotype IV was the most dominant in West Nusa Tenggara during the 2012 planting season, numbering 118 isolates or 51.0% out of the total isolates, followed by pathotype VIII (67 isolates or 29.0%), and pathotype III (47 isolates or 20.0%).</p>


Author(s):  
K.M. Muniraju ◽  
D. Pramesh ◽  
S.B. Mallesh ◽  
K. Mallikarjun ◽  
G.S. Guruprasad

2021 ◽  
Author(s):  
Guo-Bang Li ◽  
Jing Fan ◽  
Jie Liu ◽  
Jin-Long Wu ◽  
Xiao-Hong Hu ◽  
...  

Crop floral diseases are economically important as they reduce grain yield and quality and even introduce food toxins. Rice false smut has emerged as a serious floral disease producing mycotoxins. However, very little is known on the interaction mechanisms between rice flower and the causal fungus Ustilaginoidea virens. Here we show that a conserved anti-fungal immunity in rice flower is disarmed by U. virens via a secreted protein UvChi1. UvChi1 functioned as an essential virulence factor and directly interacted with the chitin receptor CEBiP and co-receptor CERK1 in rice to disrupt their oligomerizations and subsequent immune responses. Moreover, intraspecific-conserved UvChi1 could target OsCEBiP/OsCERK1 receptor complex in at least 98.5% of 5232 surveyed rice accessions. These results demonstrate that U. virens utilizes a crucial virulence factor to subvert chitin-triggered flower immunity in most rice varieties, providing new insights into the susceptibility of rice to false smut disease.


Author(s):  
Aananthi. N

Five rice cultivars viz., ASD 16, White Ponni, Pusa Basmati 1, Pusa Sugandh 4 and Pusa Sugandh 5 belonging to subspecies indica were compared for its ability in callus formation and regeneration. In this experiment, the different parameters viz., the effect of hormones (2,4-D and kinetin), organic supplement (coconut milk O1-CM 100 mll-1, O2-CM 75 mll-1, O3-CM 50 mll-1), explants (seed and immature embryo), media (MS and N6), carbon source (sucrose and maltose) using five genotypes on callus response was studied. The effect of hardening methods was also assessed. Results showed that for enhanced callus induction was with MS medium supplemented with 2.0 mgl-1 2, 4-D + 0.5 mgl-1 kinetin + 30 gl-1 maltose irrespective of explants used. Addition of 100 ml l-1 coconut milk was found have improvement in callus response. The performance of immature embryo was better than seed for callus induction, emrbyogenic callus formation, rhizogenic callus formation and regeneration. MS media provided superiority over N6. Among the genotypes Pusa Basmati 1 rendered outstanding performance in callus behavior. The treatment combination MS + 2.5 mgl-1 BAP + 0.5 mgl-1 NAA + 1.0 mgl-1 KN gave the highest organogenesis response and regeneration of plantlets. Hardening in mist chamber was recognized as the best method to give the highest per cent of regenerated plant lets.


Author(s):  
Aman Kumar Gupta ◽  
Jiwan Paudel ◽  
Dipak Yadav ◽  
Devansh Kumar ◽  
Ramu Yadav ◽  
...  

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