Contribution of methylation regulation of MpDREB2A promoter to drought resistance of Mauls prunifolia
Li, Xuewei ; Xie, Yinpeng ; Lu, Liyuan ; Yan, Mingjia ; Fang, Nan ; Xu, Jidi ; Wang, Liping ; Yan, Yan ; Zhao, Tao ; Nocker, Steve van; Ma, Fengwang ; Liang, Dong ; Guan, Qingmei - \ 2019
Plant and Soil 441 (2019)1-2. - ISSN 0032-079X - p. 15 - 32.
ChIP-seq - DNA methylation - DREB2A - Drought resistance - Gene expression - Malus
Background and aims: Malus prunifolia (Chinese name: Fu Ping Qiu Zi), a wild relative of cultivated apple (Malus x domestica Borkh), is extremely resistant to drought compared with domesticated cultivars, such as ‘Golden Delicious’. However, the molecular mechanisms underlying drought resistance of M. prunifolia have not been characterized. This study investigates a new regulatory mechanism to improve apple drought resistance. Methods: M. prunifolia and ‘Golden Delicious’ were each grafted on M. hupehensis for gene expression analysis. The methylation level of the DREB2A promoter was determined by bisulfite sequencing and ChIP-qPCR. Chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify target genes of MpDREB2A in apple. Results: The exposure to drought stress stimulated the expression level of DREB2A gene more than 100-fold in M. prunifolia, but only 16-fold in ‘Golden Delicious’. This difference in gene expression could not be explained in terms of difference in leaf relative water content. Correspondingly, the methylation level of M. prunifolia DREB2A (MpDREB2A) promoter region was significantly reduced. Additionally, MpDREB2A conferred enhanced drought resistance when ectopically expressed in Arabidopsis. Over 2800 potential downstream target genes of MpDREB2A were identified by ChIP-seq and these downstream genes have diverse potential functions related to stress resistance. Conclusions: Methylation regulation in promoter of MpDREB2A may contribute to the drought resistance of M. prunifolia.
Apple whole genome sequences : recent advances and new prospects
Peace, Cameron P. ; Bianco, Luca ; Troggio, Michela ; Weg, Eric van de; Howard, Nicholas P. ; Cornille, Amandine ; Durel, Charles Eric ; Myles, Sean ; Migicovsky, Zoë ; Schaffer, Robert J. ; Costes, Evelyne ; Fazio, Gennaro ; Yamane, Hisayo ; Nocker, Steve van; Gottschalk, Chris ; Costa, Fabrizio ; Chagné, David ; Zhang, Xinzhong ; Patocchi, Andrea ; Gardiner, Susan E. ; Hardner, Craig ; Kumar, Satish ; Laurens, Francois ; Bucher, Etienne ; Main, Dorrie ; Jung, Sook ; Vanderzande, Stijn - \ 2019
Horticulture Research 6 (2019)1. - ISSN 2052-7276
In 2010, a major scientific milestone was achieved for tree fruit crops: publication of the first draft whole genome sequence (WGS) for apple (Malus domestica). This WGS, v1.0, was valuable as the initial reference for sequence information, fine mapping, gene discovery, variant discovery, and tool development. A new, high quality apple WGS, GDDH13 v1.1, was released in 2017 and now serves as the reference genome for apple. Over the past decade, these apple WGSs have had an enormous impact on our understanding of apple biological functioning, trait physiology and inheritance, leading to practical applications for improving this highly valued crop. Causal gene identities for phenotypes of fundamental and practical interest can today be discovered much more rapidly. Genome-wide polymorphisms at high genetic resolution are screened efficiently over hundreds to thousands of individuals with new insights into genetic relationships and pedigrees. High-density genetic maps are constructed efficiently and quantitative trait loci for valuable traits are readily associated with positional candidate genes and/or converted into diagnostic tests for breeders. We understand the species, geographical, and genomic origins of domesticated apple more precisely, as well as its relationship to wild relatives. The WGS has turbo-charged application of these classical research steps to crop improvement and drives innovative methods to achieve more durable, environmentally sound, productive, and consumer-desirable apple production. This review includes examples of basic and practical breakthroughs and challenges in using the apple WGSs. Recommendations for “what’s next” focus on necessary upgrades to the genome sequence data pool, as well as for use of the data, to reach new frontiers in genomics-based scientific understanding of apple.
An atypical R2R3 MYB transcription factor increases cold hardiness by CBF-dependent and CBF-independent pathways in apple
Xie, Yinpeng ; Chen, Pengxiang ; Yan, Yan ; Bao, Chana ; Li, Xuewei ; Wang, Liping ; Shen, Xiaoxia ; Li, Haiyan ; Liu, Xiaofang ; Niu, Chundong ; Zhu, Chen ; Fang, Nan ; Shao, Yun ; Zhao, Tao ; Yu, Jiantao ; Zhu, Jianhua ; Xu, Lingfei ; Nocker, Steven van; Ma, Fengwang ; Guan, Qingmei - \ 2018
New Phytologist 218 (2018)1. - ISSN 0028-646X - p. 201 - 218.
Apple (Malus × domestica) - C-REPEAT BINDING FACTOR (CBF) - Cold hardiness - MdMYB124 - MdMYB88
Apple (Malus × domestica) trees are vulnerable to freezing temperatures. However, there has been only limited success in developing cold-hardy cultivars. This lack of progress is due at least partly to lack of understanding of the molecular mechanisms of freezing tolerance in apple. In this study, we evaluated the potential roles for two R2R3 MYB transcription factors (TFs), MYB88 and the paralogous FLP (MYB124), in cold stress in apple and Arabidopsis. We found that MYB88 and MYB124 positively regulate freezing tolerance and cold-responsive gene expression in both apple and Arabidopsis. Chromatin-Immunoprecipitation-qPCR and electrophoretic mobility shift assays showed that MdMYB88/MdMYB124 act as direct regulators of the COLD SHOCK DOMAIN PROTEIN 3 (MdCSP3) and CIRCADIAN CLOCK ASSOCIATED 1 (MdCCA1) genes. Dual luciferase reporter assay indicated that MdCCA1 but not MdCSP3 activated the expression of MdCBF3 under cold stress. Moreover, MdMYB88 and MdMYB124 promoted anthocyanin accumulation and H2O2 detoxification in response to cold. Taken together, our results suggest that MdMYB88 and MdMYB124 positively regulate cold hardiness and cold-responsive gene expression under cold stress by C-REPEAT BINDING FACTOR (CBF)-dependent and CBF-independent pathways.
Optimizing odor identification testing as quick and accurate diagnostic tool for Parkinson's disease
Mahlknecht, Philipp ; Pechlaner, Raimund ; Boesveldt, Sanne ; Volc, Dieter ; Pinter, Bernardette ; Reiter, Eva ; Müller, Christoph ; Krismer, Florian ; Berendse, Henk W. ; Hilten, Jacobus J. van; Wuschitz, Albert ; Schimetta, Wolfgang ; Högl, Birgit ; Djamshidian, Atbin ; Nocker, Michael ; Göbel, Georg ; Gasperi, Arno ; Kiechl, Stefan ; Willeit, Johann ; Poewe, Werner ; Seppi, Klaus - \ 2016
Movement Disorders 31 (2016)9. - ISSN 0885-3185 - p. 1408 - 1413.
diagnosis - olfactory dysfunction - Parkinson's disease - parkinsonism - tremor
Introduction: The aim of this study was to evaluate odor identification testing as a quick, cheap, and reliable tool to identify PD. Methods: Odor identification with the 16-item Sniffin' Sticks test (SS-16) was assessed in a total of 646 PD patients and 606 controls from three European centers (A, B, and C), as well as 75 patients with atypical parkinsonism or essential tremor and in a prospective cohort of 24 patients with idiopathic rapid eye movement sleep behavior disorder (center A). Reduced odor sets most discriminative for PD were determined in a discovery cohort derived from a random split of PD patients and controls from center A using L1-regularized logistic regression. Diagnostic accuracy was assessed in the rest of the patients/controls as validation cohorts. Results: Olfactory performance was lower in PD patients compared with controls and non-PD patients in all cohorts (each P <0.001). Both the full SS-16 and a subscore of the top eight discriminating odors (SS-8) were associated with an excellent discrimination of PD from controls (areas under the curve ≥0.90; sensitivities ≥83.3%; specificities ≥82.0%) and from non-PD patients (areas under the curve ≥0.91; sensitivities ≥84.1%; specificities ≥84.0%) in all cohorts. This remained unchanged when patients with >3 years of disease duration were excluded from analysis. All 8 incident PD cases among patients with idiopathic rapid eye movement sleep behavior disorder were predicted with the SS-16 and the SS-8 (sensitivity, 100%; positive predictive value, 61.5%). Conclusions: Odor identification testing provides excellent diagnostic accuracy in the distinction of PD patients from controls and diagnostic mimics. A reduced set of eight odors could be used as a quick tool in the workup of patients presenting with parkinsonism and for PD risk indication.