PlantSize Offers an Affordable, Non-destructive Method to Measure Plant Size and Color in Vitro

Abstract

Plant size, shape and color are important parameters of plants, which have traditionally been measured by destructive and time-consuming methods. Non-destructive image analysis is an increasingly popular technology to characterize plant development in time. High throughput automatic phenotyping platforms can simultaneously analyze multiple morphological and physiological parameters of hundreds or thousands of plants. Such platforms are, however, expensive and are not affordable for many laboratories. Moreover, determination of basic parameters is sufficient for most studies. Here we describe a non-invasive method, which simultaneously measures basic morphological and physiological parameters of in vitro cultured plants. Changes of plant size, shape and color is monitored by repeated photography with a commercial digital camera using neutral white background. Images are analyzed with the MatLab-based computer application PlantSize, which simultaneously calculates several parameters including rosette size, convex area, convex ratio, chlorophyll and anthocyanin contents of all plants identified on the image. Numerical data are exported in MS Excel-compatible format. Subsequent data processing provides information on growth rates, chlorophyll and anthocyanin contents. Proof-of-concept validation of the imaging technology was demonstrated by revealing small but significant differences between wild type and transgenic Arabidopsis plants overexpressing the HSFA4A transcription factor or the hsfa4a knockout mutant, subjected to different stress conditions. While HSFA4A overexpression was associated with better growth, higher chlorophyll and lower anthocyanin content in saline conditions, the knockout hsfa4a mutant showed hypersensitivity to various stresses. Morphological differences were revealed by comparing rosette size, shape and color of wild type plants with phytochrome B (phyB-9) mutant. While the technology was developed with Arabidopsis plants, it is suitable to characterize plants of other species including crops, in a simple, affordable and fast way. PlantSize is publicly available (http://www.brc.hu/pub/psize/index.html).

Characterization of Biostimulant Mode of Action Using Novel Multi-Trait High-Throughput Screening of Arabidopsis Germination and Rosette Growth

“…The method of Granier et al (2006) showed possibilities solving potential complications and methodological difficulties with the spatial and temporal variability of micrometeorological conditions within a growth chamber, reaching throughput of 500 plants per hour. Recently, simple HTS protocol based on in vitro growth of Arabidopsis using square plates with 16 seedlings and manual image acquisition followed by analysis of plant size and color was published by Faragó et al (2018) . The protocol presented by us is based on our previous report of an automated method for HTS of Arabidopsis rosette growth in multi-well plates accessible at OloPhen facility ( De Diego et al, 2017 ).…”

“…As presented here, our new method allows a simultaneous study of different growth conditions without compromising the number of variants, replicates and plants per treatment. Moreover, compared to Faragó et al (2018) , the growth analysis of each plant is done for the whole cycle by imaging of the same plant individual. Further, the use of independent wells per plant permits an easier detection of the single plant so they are located in a concrete XY position.…”

Functional Analysis of the Arabidopsis thaliana CDPK-Related Kinase Family: AtCRK1 Regulates Responses to Continuous Light

“…Two biological repetitions were performed. Chlorophyll and carotenoid contents were determined as described in [ 64 ]. Chlorophyll absorbance values were measured at 470, 648 and 664 nm between OD 0.3 and 0.8 using a Multiskan G0 spectrophotometer (Thermo Fischer Scientific, Vantaa, Finland).…”

“…Chlorophyll absorbance values were measured at 470, 648 and 664 nm between OD 0.3 and 0.8 using a Multiskan G0 spectrophotometer (Thermo Fischer Scientific, Vantaa, Finland). Chlorophyll concentrations were calculated with equations as described in [ 64 ].…”

Characterization of the Plant Growth-Promoting Activities of Endophytic Fungi Isolated from Sophora flavescens

“…Primary root growth was measured every 24 h for 4 days. The fresh weights of the plants from each plate were measured, and photosynthetic pigments were quantified, as described by Faragó et al [38].…”