Genetic mapping of the early responses to salt stress inArabidopsis thaliana

Abstract

Summary Salt stress decreases plant growth prior to significant ion accumulation in the shoot. However, the processes underlying this rapid reduction in growth are still unknown. To understand the changes in salt stress responses through time and at multiple physiological levels, examining different plant processes within a single set‐up is required. Recent advances in phenotyping has allowed the image‐based estimation of plant growth, morphology, colour and photosynthetic activity. In this study, we examined the salt stress‐induced responses of 191 Arabidopsis accessions from 1 h to 7 days after treatment using high‐throughput phenotyping. Multivariate analyses and machine learning algorithms identified that quantum yield measured in the light‐adapted state (Fv′/Fm′) greatly affected growth maintenance in the early phase of salt stress, whereas the maximum quantum yield (QYmax) was crucial at a later stage. In addition, our genome‐wide association study (GWAS) identified 770 loci that were specific to salt stress, in which two loci associated with QYmax and Fv′/Fm′ were selected for validation using T‐DNA insertion lines. We characterized an unknown protein kinase found in the QYmax locus that reduced photosynthetic efficiency and growth maintenance under salt stress. Understanding the molecular context of the candidate genes identified will provide valuable insights into the early plant responses to salt stress. Furthermore, our work incorporates high‐throughput phenotyping, multivariate analyses and GWAS, uncovering details of temporal stress responses and identifying associations across different traits and time points, which are likely to constitute the genetic components of salinity tolerance.

Phenotyping a diversity panel of quinoa using UAV-retrieved leaf area index, SPAD-based chlorophyll and a random forest approach

“…In addition, observations from multiple sensors may assist in identifying accessions with high salinity tolerance. For example, Awlia et al, (2016Awlia et al, ( , 2021 used red-green-blue (RGB) and chlorophyll fluorescence (ChlF) imaging to capture the growth, morphology, color and photosynthetic performance for identifying salt tolerance in Arabidopsis thaliana plants. Malbeteau et al (2021) and Stutsel et al (2021) used UAV-based thermal data to monitor canopy temperature of wild tomato species in response to salt stress.…”

Key Cannabis Salt-Responsive Genes and Pathways Revealed by Comparative Transcriptome and Physiological Analyses of Contrasting Varieties

“…The HKT gene family [77], SNRK gene family [78], SPL gene family [79] and PGDH gene family [80], among others, have been identified to regulate salt stress. Correlational research has presented considerable progress in exploring the salt responses of major plants, such as Arabidopsis [81][82][83], soybean [84][85][86], rice [87][88][89] and maize [90][91][92]. Plant breeders and biotechnologists have tried to develop crop varieties with a strong capacity to respond to salt stress, mainly including improving the plant's salt tolerant and salt resistance.…”

Image-based assessment of plant disease progression identifies new genetic loci for resistance

“…Imaged-based phenotyping has been used to detect QTL associated with plant root 32 and shoot [33][34][35] architecture, plant height 36 , salt stress 37 , and yield 38,39 among other traits. Although imagebased phenotyping has become increasingly common to quantify plant disease symptoms [4][5][6][7][11][12][13][14][15][16] , to our knowledge, it has yet to be used in the identification of new genetic loci for disease resistance.…”