bioRxiv Science⌕ Search

bioRxiv · 10.1101/152702

Combining semi-automated image analysis techniques with machine learning algorithms to accelerate large scale genetic studies

Abstract

BackgroundGenetic analyses of plant root system development require large datasets of extracted architectural traits. To quantify such traits from images of root systems, researchers often have to choose between automated tools (that are prone to error and extract only a limited number of architectural traits) or semi-automated ones (that are highly time consuming).\n\nFindingsWe trained a Random Forest algorithm to infer architectural traits from automatically-extracted image descriptors. The training was performed on a subset of the dataset, then applied to its entirety. This strategy allowed us to (i) decrease the image analysis time by 73% and (ii) extract meaningful architectural traits based on image descriptors. We also show that these traits are sufficient to identify Quantitative Trait Loci that had previously been discovered using a semi-automated method.\n\nConclusionsWe have shown that combining semi-automated image analysis with machine learning algorithms has the power to increase the throughput in large scale root studies. We expect that such an approach will enable the quantification of more complex root systems for genetic studies. We also believe that our approach could be extended to other area of plant phenotyping.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Atkinson, J. A., Lobet, G., Noll, M., Meyer, P. E., Griffiths, M., Wells, D. M.. 2017-06-20. Combining semi-automated image analysis techniques with machine learning algorithms to accelerate large scale genetic studies. https://doi.org/10.1101/152702

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Photosynthesis-derived carbohydrate supply sustains CuCl2-induced phytoalexin production in rice leaves

Phytoalexins are antimicrobial metabolites whose biosynthesis is triggered by signaling activated by both biotic and abiotic elicitors, but the physiological conditions that sustain their production remain poorly understood. Here, we examined how light and carbohydrate availability affect CuCl2-induced production of diterpenoid (phytocassanes and momilactones) and flavonoid (sakuranetin) phytoalexins in rice (Oryza sativa L.) leaf disks. Darkness strongly suppressed both the accumulation of all three phytoalexin groups and the induction of their biosynthetic genes. In darkness, endogenous sucrose, glucose, and fructose declined to 3%-8% of the levels in the light, whereas early accumulation of jasmonic acid and jasmonoyl-L-isoleucine (JA-Ile) was not detectably reduced. Exogenous sucrose restored phytoalexin accumulation in darkness in a dose-dependent manner, together with the expression of the suppressed biosynthetic genes, whereas equimolar mannitol had no effect. Glucose also restored sakuranetin accumulation in darkness but only partially restored diterpenoid accumulation, whereas the glucose analog 2-deoxy-D-glucose did not, and it suppressed CuCl2-induced accumulation in the light in a dose-dependent manner. In the light, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosynthetic electron transport, depleted soluble sugars and suppressed phytoalexin accumulation, and sucrose reversed this suppression. Sugars alone induced little phytoalexin accumulation, indicating that carbohydrates act permissively rather than as elicitors. Diterpenoid phytoalexins depended more strongly on light than sakuranetin, yet both classes depended on carbohydrate availability. These results indicate that photosynthesis-derived carbohydrate supply sustains elicitor-induced phytoalexin production in rice leaves and largely accounts for its light dependence.

plant biology↗

Transcriptome analysis provides insights into candidate genetic regulators of birch response to salt stress

Abstract Background: Soil salinization is a worldwide matter of concern and can result in a series of agricultural and ecological problems. Previous transcriptome data have shown genetic regulatory mechanisms of salt stress response in a salt-tolerant species of Betula halophila and a salt-sensitive species of B. platyphylla, but comparative analysis of transcriptional changes in the the two species remains limited. Aims: We compared gene expression in leaves of B. halophila and leaves and roots of B. platyphylla. Methods: Differentially expressed genes (DEGs) were identified after 24 h of salt stress, followed by Gene Ontology enrichment and gene regulatory network (GRN) construction. Selected DEGs were examined by quantitative real-time PCR (RT-qPCR). Results: Compared with 0 h, 956 DEGs were found in B. halophila leaves (BHLeaf), 2,955 in B. platyphylla leaves (BPLeaf), and 3,827 in B. platyphylla roots (BPRoot). BHLeaf DEG expression patterns were similar to those of BPRoot. DEGs from BHLeaf and BPRoot were enriched in cell wall organization or biogenesis, whereas hormone biosynthesis and signaling genes were altered mainly in B. platyphylla. RT-qPCR showed that selected DEGs were induced by 200 mM NaCl for 24 h in B. platyphylla. Conclusions: Our work uncovered genetic mechanisms of salt stress response commonly and uniquely occurring in two birch species and provides resources for breeding salt-tolerant birch.

plant biology↗

Minimal requirements and evolution of polar membrane targeting in the land plant SOSEKI protein family

Accurate spatial distribution of polar proteins is essential for cell function, but mechanisms underlying polar protein targeting in plants are poorly understood. Here, we dissect the molecular mechanisms underlying the polar targeting of the SOSEKI1 (SOK1) protein in Arabidopsis thaliana. Using extensive mutagenesis and truncation analyses of the polarity domain, we mapped the minimal polarity fragment necessary and sufficient for stable polar targeting to a 25-amino-acid region. This region likely forms an amphipathic helix, and mutations reveal that both its polar and apolar faces are essential for membrane association and polarity. Using phylogenetic analysis, we reconstruct the evolutionary history of the minimal polar targeting region across land plants. Using cross-species expression and protein localization, we infer the ancestral polar SOK localization pattern and show how it remained remarkably conserved, only to diversify upon gene duplication. This work identifies a polar targeting peptide in plants, reveals a mechanism for polar membrane targeting of a plant protein family, and demonstrates both conservation and diversification within this family.

plant biology↗