Erik Alexandersson

Erik Alexandersson
Swedish University of Agricultural Sciences | SLU · Department of Plant Protection Biology

PhD

About

71
Publications
17,773
Reads
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2,439
Citations
Introduction
Additional affiliations
May 2016 - present
Swedish University of Agricultural Sciences
Position
  • Professor (Associate)
July 2011 - May 2016
Swedish University of Agricultural Sciences
Position
  • Professor (Assistant)

Publications

Publications (71)
Preprint
Full-text available
Effective early detection of potato late blight (PLB) is an essential aspect of potato cultivation. However, it is a challenge to detect late blight at an early stage in fields with conventional imaging approaches because of the lack of visual cues displayed at the canopy level. Hyperspectral imaging can, capture spectral signals from a wide range...
Article
Full-text available
Multiple biotic and abiotic stresses challenge plants growing in agricultural fields. Most molecular studies have aimed to understand plant responses to challenges under controlled conditions. However, studies on field-grown plants are scarce, limiting application of the findings in agricultural conditions. In this study, we investigated the compos...
Chapter
Field phenotyping of crops has recently gained considerable attention leading to the development of new protocols for recording plant traits of interest. Phenotyping in field conditions can be performed by various cameras, sensors, and imaging platforms. In this chapter, practical aspects as well as advantages and disadvantages of aboveground pheno...
Article
The plant pathogen Phytophthora infestans causes the severe disease late blight in potato, which can result in huge yield loss for potato production. Automatic and accurate disease lesion segmentation enables fast evaluation of disease severity and assessment of disease progress. In tasks requiring computer vision, deep learning has recently gained...
Article
Full-text available
Section Key Message Using disease bioassays and transcriptomic analysis we show that intact SA-signalling is required for potato defences against the necrotrophic fungal pathogen Alternaria solani. AbstractSection Abstract Early blight, caused by the necrotrophic fungus Alternaria solani, is an increasing problem in potato cultivation. Studies of t...
Preprint
Full-text available
The plant pathogen Phytophthora infestans causes the severe disease late blight in potato, which results in a huge loss for potato production. Automatic and accurate disease lesion segmentation enables fast evaluation of disease severity and assessment of disease progress for precision crop breeding. Deep learning, specifically a deep convolutional...
Article
Currently available fungicides against potato late blight are effective but there are concerns about the sustainability of frequent applications and the risks of fungicide resistance. Therefore, we investigated how potassium phosphite can be integrated into late blight control programs with reduced fungicides in field trials. Phosphite was somewhat...
Article
Full-text available
The prevalence of vitamin A deficiency in sub-Saharan Africa necessitates effective approaches to improve provitamin A content of major staple crops. Cassava holds much promise for food security in sub-Saharan Africa, but a negative correlation between β-carotene, a provitamin A carotenoid, and dry matter content has been reported, which poses a ch...
Article
Full-text available
Background: Potato is the third most consumed crop in the world. Breeding for traits such as yield, product quality and pathogen resistance are main priorities. Identifying molecular signatures of these and other important traits is important in future breeding efforts. In this study, a progeny population from a cross between a breeding line, SW93...
Preprint
Full-text available
Background Potato is the third most consumed crop in the world. Breeding for traits such as yield, product quality and pathogen resistance are main priorities. Identifying molecular signatures of these and other important traits is important in future breeding efforts. In this study, a progeny population from a cross between a breeding line, SW93-1...
Article
Full-text available
This review provides a summary of botanicals and plant strengtheners that have potential uses for disease and pest management in potato and tomato cultivation in African. We discuss their possible use to prevent major diseases and pests which infest potato and tomato, such as early and late blight, bacterial wilt, potato tuber moth, and tomato leaf...
Preprint
Full-text available
Background Potato is the third most consumed crop in the world. Breeding for traits such as yield, product quality and pathogen resistance are main priorities. Identifying molecular signatures of these and other important traits is important in future breeding efforts. In this study, a progeny population from a cross between a breeding line, SW93-1...
Preprint
Full-text available
Background Potato is the third most consumed crop in the world. Breeding for traits such as yield, product quality and pathogen resistance are main priorities. Identifying molecular signatures of these and other important traits is important in future breeding efforts. In this study, a progeny population from a cross between a breeding line, SW93-1...
Article
Full-text available
High-throughput field phenotyping has garnered major attention in recent years leading to the development of several new protocols for recording various plant traits of interest. Phenotyping of plants for breeding and for precision agriculture have different requirements due to different sizes of the plots and fields, differing purposes and the urg...
Article
Late blight caused by the oomycete Phytophthora infestans is one of the most severe diseases of potato (Solanum tuberosum L.) and tomato (Solanum lycopersicum L.). In this study, field trials were conducted in a cool tropical highland of Ethiopia for three consecutive years to investigate the efficacy of phosphite alone and in combination with conv...
Article
Full-text available
BACKGROUND The potato tuber moth (PTM) (Phthorimaea operculella) is a pest of solanaceous species that causes serious damage to potato tubers and tomato fruits. Control is mainly dependent on the use of synthetic chemicals, which pose a risk to the environment and health of farmers, especially in developing countries where application safety rules...
Article
Full-text available
Plant phenomics refers to the systematic study of plant phenotypes. Together with closely monitored, controlled climates, it provides an essential component for the integrated analysis of genotype-phenotype-envi-ronment interactions. Currently, several plant growth and phenotyping facilities are under establishment globally, and numerous facilities...
Article
Full-text available
Potato cyst nematodes (PCN) are important pests in crop production, especially since they persist in the soil and may affect further potato production for many years. Little is known about putative resistance and susceptibility targets as well as the general signaling in potato after interactions with PCN. Here we characterize a new potato breeding...
Article
Full-text available
This review provides a current summary of plant resistance inducers (PRIs) that have been successfully used in the Solanaceae plant family to protect against pathogens by activating the plant’s own defence. Solanaceous species include many important crops such as potato and tomato. We also present findings regarding the molecular processes after ap...
Article
Full-text available
Potato late blight caused by the oomycete Phytophthora infestans is a devastating disease of potato worldwide. Most of the potato cultivars grown in conventional agriculture are susceptible, or at best moderately resistant, and require frequent applications of fungicides to avoid heavy yield losses.
Article
Non-genetic inheritance, e.g. transgenerational epigenetic effects, has received increasing interest in recent years, particularly in plants. However, most studies have involved a few model species and relatively little is known about wild species in these respects. We investigated transgenerational induced resistance to infection by the devastatin...
Article
Full-text available
Selected reaction monitoring (SRM) is a targeted mass spectrometry technique which enables precise quantitation of hundreds of peptides in a single run. This technique provides new opportunities for multiplexed protein biomarker measurements. For precision plant breeding, DNA based markers have been used extensively, but the potential of protein bi...
Article
Full-text available
In this study the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in Vitis vinifera L. cv. Sauvignon Blanc berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries...
Article
Full-text available
Comparative transcriptomics between species can provide valuable understanding of plant-pathogen interactions. Here, we focus on wild Solanum species and potato clones with varying degree of resistance against Phytophthora infestans, which causes the devastating late blight disease in potato. The transcriptomes of three wild Solanum species native...
Article
Full-text available
Pathogen attack and the plant's response to this attack affect herbivore oviposition preference and larval performance. Introduction of major resistance genes against Phytophthora infestans (Rpi-genes), the cause of the devastating late blight disease, from wild Solanum species into potato changes the plant-pathogen interaction dynamics completely,...
Article
Full-text available
Nonalcoholic fatty liver disease (NAFLD) is a risk factor for Hepatocellular carcinoma (HCC), but he transition from NAFLD to HCC is poorly understood. Feature selection algorithms in human and genetically modified mice NAFLD and HCC microarray data were applied to generate signatures of NAFLD progression and HCC differential survival. These signat...
Article
A biological pathway is the set of molecular entities involved in a given biological process, and the interrelations among them. Even though biological pathways have been studied extensively, discovering missing genes in pathways remains a fundamental challenge. Here, we present an easy-to-use tool that allows users to run MORPH (MOdule-guided Rank...
Article
Full-text available
Background For most organisms, even if their genome sequence is available, little functional information about individual genes or proteins exists. Several annotation pipelines have been developed for functional analysis based on sequence, `omics¿, and literature data. However, researchers encounter little guidance on how well they perform. Here, w...
Article
Full-text available
Background Potato late blight caused by the oomycete pathogen Phytophthora infestans can lead to immense yield loss. We investigated the transcriptome of Solanum tubersoum (cv. Desiree) and characterized the secretome by quantitative proteomics after foliar application of the protective agent phosphite. We also studied the distribution of phosphite...
Article
Full-text available
The recent advances in gene expression analysis as well as protein and metabolite quantification enable genome-scale capturing of complex biological processes at the molecular level in crop field trials. This opens up new possibilities for understanding the molecular and environmental complexity of field-based systems and thus shedding light on the...
Article
Full-text available
Background In order to get global molecular understanding of one of the most important crop diseases worldwide, we investigated compatible and incompatible interactions between Phytophthora infestans and potato (Solanum tuberosum). We used the two most field-resistant potato clones under Swedish growing conditions, which have the greatest known loc...
Article
Full-text available
High-throughput omics data often contain systematic biases introduced during various steps of sample processing and data generation. As the source of these biases is usually unknown, it is difficult to select an optimal normalization method for a given dataset. To facilitate this process, we introduce the open-source tool "Normalyzer". It normalize...
Article
Full-text available
Induced resistance (IR) can be part of a sustainable plant protection strategy against important plant diseases. beta-aminobutyric acid (BABA) can induce resistance in a wide range of plants against several types of pathogens, including potato infected with Phytophthora infestans. However, the molecular mechanisms behind this are unclear and seem t...
Article
Full-text available
The plant secretome refers to the set of proteins secreted out of the plant cell into the surrounding extracellular space commonly referred to as the apoplast. Secreted proteins maintain cell structure and acts in signaling and are crucial for stress responses where they can interact with pathogen effectors and control the extracellular environment...
Article
Full-text available
Background Carotenoids are a heterogeneous group of plant isoprenoids primarily involved in photosynthesis. In plants the cleavage of carotenoids leads to the formation of the phytohormones abscisic acid and strigolactone, and C13-norisoprenoids involved in the characteristic flavour and aroma compounds in flowers and fruits and are of specific im...
Data
Photosynthetic pigments concentrations and ratios in three berry developmental stages. Photosynthetic pigments extracted from green, véraison and ripe/harvest stage berries were separated by HPLC and quantified relative to authentic standards. Average carotenoid and chlorophyll concentrations in berries are shown in ng/mg FW, with the respective st...
Data
Chromosomal localisation of the carotenoid metabolic genes. The 37 of the 42 carotenoid metabolic pathway members are depicted on the heterozygous ENTAV115 V. vinifera L. cv Pinot noir genome sequence assembly together with the closest genetic markers and with other well distributed markers along the chromosomes as taken from Troggio et al. [[18].]...
Data
Expression of the carotenoid biosynthetic/catabolic genes at the three berry developmental stages. Average expression values of the carotenoid metabolic genes at the three stages of berry development (E-L stage 31, -34 and −38). Average expression values from the Nimblegen whole-genome grape arrays are shown with their standard deviations (n = 3)....
Data
Plasmids and constructs used in this study. Plasmids constructed in this study were named according to the carotenoid biosynthetic/catabolic gene they contained. The primers used and the size of the PCR product cloned are listed in the respective columns.
Data
Gene names, relevant accession numbers and putative gene assignments for the predicted genes encodingcarotenoid biosynthetic and catabolic enzymes. Gene sequences isolated in this study are underlined.
Data
Full-text available
Abscisic acid concentration in the three berry developmental stages. Abscisic acid was extracted from the three stages of berry development (E-L stage 31, -34 and −38) and analysed using UPLC MS/MS and quantified relative to an authentic standard. Abscisic acid concentrations in berries are shown in ng/g FW, with the respective standard deviations...
Data
PCR primers used in this study. The table lists the primers used, the respective sequences, melting temperatures (Tm’s) and a brief description of the amplified product. Where applicable, restriction sites incorporated to facilitate cloning are indicated in lowercase letters in the respective primer sequence.
Presentation
Presented at the 38th Annual Congress of the South African Association of Botanists held at the University of Pretoria, Pretoria, 15-18 January 2012
Data
A selection of differentially expressed genes. Probes are divided into orthologous clusters based on sequence similarity and expression ratios are given in Log2-scale. Top hits based on sequence similarity are given for either Arabidopsis or rice and includes the corresponding gene description. Related citations are given in the heading literature....
Data
Updated Gene Ontology (GO terms) associated with each probe on the TIGR 10 k microarray. Updated GO terms associated with each probe on the TIGR 10 k microarray. GO terms were updated with information retrieved from nine plant species with the help of a graph structure. The table is compatible for use with GOEast if saved as a tab-delimited file.
Data
Gene ontology enrichments. GO enrichment of probes showing significant difference in signal intensity in Vvpgip1 line 37 and 45 in comparison to WT. (A) Biological process (B) Cellular compartment and (C) Molecular function. The gene ontology maps were generated in GOEast [39]. Enriched terms are colored in yellow and the intensity of the color yel...
Data
Full-text available
MapMan overview of metabolic categories comparing Vvpgip1 line 37 and 45. A MapMan mapping file adopted for the TIGR 10 K potato microarray was used [41]. Expression values were filtered after FDR-adjustment (p < 0.05).
Data
Table of probes displaying differential expression. Table of all probes displaying differential expression. Differential expression (Log2) between control plants and Vvpgip1-transformed lines 37 and 45 (FDR <0.05). Probes are divided into orthologous clusters based on sequence similarity (see Materials and Methods). Functional category, name, an ar...
Article
Full-text available
Polygalacturonase-inhibiting proteins (PGIPs) directly limit the effective ingress of fungal pathogens by inhibiting cell wall-degrading endopolygalacturonases (ePGs). Transgenic tobacco plants over-expressing grapevine (Vitis vinifera) Vvpgip1 have previously been shown to be resistant to Botrytis infection. In this study we characterized two of t...
Article
Full-text available
When performing functional and structural studies, large quantities of pure protein are desired. Most membrane proteins are however not abundantly expressed in their native tissues, which in general rules out purification from natural sources. Heterologous expression, especially of eukaryotic membrane proteins, has also proven to be challenging. Th...
Article
Aquaporins facilitate water transport over cellular membranes, and are therefore believed to play an important role in water homeostasis. In higher plants aquaporin-like proteins, also called major intrinsic proteins (MIPs), are divided into five subfamilies. We have previously shown that MIP transcription in Arabidopsis thaliana is generally downr...
Article
Loss of aquaporin TIP1;1 in Arabidopsis has been suggested to result in early senescence and plant death. This was based on the fact that a partial reduction of TIP1;1 by RNA interference (RNAi) led to gradual phenotypes, ranging from indistinguishable from wild type to lethality, depending on the degree of downregulation of the target messenger, a...
Article
Full-text available
All techniques needed for proteomic analyses of plant plasma membranes are described in detail, from isolation of plasma membranes to protein identification by mass spectrometry (MS). Plasma membranes are isolated by aqueous two-phase partitioning yielding vesicles with a cytoplasmic side-in orientation and a purity of about 95%. These vesicles are...