scholarly journals Hydroxybenzoate hydroxylase genes underlying protocatechuic acid production in Valsa mali are required for full pathogenicity in apple trees

2021 ◽  
Author(s):  
Lulu Meng ◽  
Cuicui Sun ◽  
Liyong Gao ◽  
Muhammad Saleem ◽  
Baohua Li ◽  
...  
Keyword(s):  
Acid Production ◽  
Protocatechuic Acid ◽  
Apple Trees ◽  
Hydroxybenzoate Hydroxylase ◽  
Valsa Mali

scholarly journals Latent Infection of Valsa mali in the Seeds, Seedlings and Twigs of Crabapple and Apple Trees is a Potential Inoculum Source of Valsa Canker

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiang-long Meng ◽  
Xing-hua Qi ◽  
Ze-yuan Han ◽  
Yong-bin Guo ◽  
Ya-nan Wang ◽  
...  
Keyword(s):  
Latent Infection ◽  
Apple Trees ◽  
Inoculum Source ◽  
Valsa Canker ◽  
Valsa Mali

The influence of lower temperature induction of Valsa mali on the infection of apple trees

Plant Disease ◽  
2021 ◽  
Author(s):  
Xianglong Meng ◽  
Rui Yang ◽  
An-Tai Liu ◽  
Tongle Hu ◽  
Yanan Wang ◽  
...  
Keyword(s):  
Cold Treatment ◽  
Colony Growth ◽  
Lesion Length ◽  
Cell Wall Degrading Enzymes ◽  
Apple Trees ◽  
Temperature Changes ◽  
Valsa Canker ◽  
Pre Treatment ◽  
Lower Temperature ◽  
Valsa Mali

Apple valsa canker (AVC), caused by Valsa mali (Vm), is one of the most important diseases of apple trees in China. AVC occurred severely along with cold winter or cold spring. However, the effect of lower temperature on Vm is poorly understood. This study evaluated the influence of lower temperature pre-treatment of Vm on the infection of apple twigs and leaves. The results showed that exposing of Vm at lower temperature (between -10°C and 10°C) for more than 18 h significantly increased the disease severity of apple leaves and twigs, with a higher LAR, lesion length and DI than that at 25°C. In addition, cold treatment ranging from -5°C to 10°C promoted the colony growth. Meanwhile, the relative expression of four cell wall degrading enzymes (CWDEs) related genes pre-treated at -5°C and 5°C were significantly higher than that at 25°C. The results indicated that the virulence of Vm mycelium is sensitivity for lower temperature change. After sensing lower temperature changes, Vm can adjust its infection of apple trees by regulating the expression of pathogenicity gene and growth rate. Spring is the season with very frequent temperature changes, and Vm is highly invasive in this season. Therefore, more attention should be paid in spring to protecting apple trees from infection by Vm, such as reduction of pruning wounds formation in spring, and application of protective agents to the pruning wounds in time.

Lignin valorization for protocatechuic acid production in engineered Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Ren-Kuan Zhang ◽  
Yong-Shui Tan ◽  
You-Zhi Cui ◽  
Xin Xin ◽  
Zhi-Hua Liu ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acid Production ◽  
Protocatechuic Acid ◽  
Lignin Valorization ◽  
Engineered Saccharomyces Cerevisiae

A biological funnel pathway was established for the production of protocatechuic acid from lignin in engineered Saccharomyces cerevisiae.

scholarly journals A Nested PCR Assay for Detecting Valsa mali var. mali in Different Tissues of Apple Trees

Plant Disease ◽  
2012 ◽  
Vol 96 (11) ◽  
pp. 1645-1652 ◽  
Author(s):  
Rui Zang ◽  
Zhiyuan Yin ◽  
Xiwang Ke ◽  
Xiaojie Wang ◽  
Zhengli Li ◽  
...  
Keyword(s):  
Nested Pcr ◽  
Detection Rate ◽  
Pcr Analysis ◽  
Pcr Assay ◽  
Apple Trees ◽  
Specific Primers ◽  
Fungal Isolation ◽  
Species Specific ◽  
Valsa Mali ◽  
Different Tissues

A nested polymerase chain reaction (PCR) assay for detecting Valsa mali var. mali, the causal agent of apple tree Valsa canker, was developed. One pair of genus-specific primers was designed based on the ribosomal DNA internal transcribed spacer conservative sequence of the Valsa genus and one pair of species-specific primers was designed based on the specific sequence of V. mali var. mali. The specificity of the genus-specific and species-specific primers was evaluated against 10 V. mali var. mali isolates, 10 V. mali var. pyri isolates, 4 isolates from closely related Valsa spp., and 8 isolates from fungal species that are commonly isolated from naturally infected apple bark tissue. A distinct band of 348 bp in length was detected in all V. mali var. mali isolates but not in other tested species and the V. mali var. pyri variety. The sensitivity of this assay was evaluated by serial dilutions of DNA extracted from V. mali var. mali pure cultures and apple bark tissues with or without visible symptoms. The results showed that the assay was able to detect as little as 100 fg of DNA in mycelial samples and apple bark tissues with visible symptoms, whereas the lowest detectable concentration was 10 pg of DNA in symptomless apple bark tissues. The efficiency of the nested PCR assay was compared with that of fungal isolation assays. All symptomless and symptomatic samples from which the pathogen was successfully isolated yielded a PCR product of the expected size. The detection rate of nested PCR for symptomless samples was 64.7%, which was much higher than the detection rate of 20.6% by fungal isolation. The PCR analysis of different symptomless tissues showed that the incidence of V. mali var. mali was different in different tissues of apple trees. The average incidence of V. mali var. mali was 89% in terminal buds, 71% in internodes, and 48% in bud scale scars. Moreover, the incidence of V. mali var. mali in nonsymptomatic tissues was higher in orchards where more trees were infected. Taken together, the assay developed in this study can be used for rapid and reliable detection of V. mali var. mali in tissues of apple trees with or without symptoms and also for monitoring the presence of the pathogen at an early stage of disease development.

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