Salinity tolerance

Taking the kinks out of curves

In a recent paper, researchers have developed a methodology suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.

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An example of curve registration.  a The salinity sensitivity (SS) curves of the 16 functions from an arbitrary family, b SS curves after the curve registration, and c the corresponding time-warping functions. The salinity sensitivity on the y-axis of a and b refers to the derivative of the relative decrease in plant biomass

 

Advanced high-throughput technologies and equipment allow the collection of large and reliable data sets related to plant growth. These data sets allow us to explore salt tolerance in plants with sophisticated statistical tools.

As agricultural soils become more saline, analysis of salinity tolerance in plants is necessary for our understanding of plant growth and crop productivity under saline conditions. Generally, high salinity has a negative effect on plant growth, causing decreases in productivity.  The response of plants to soil salinity is dynamic, therefore requiring the analysis of growth over time to identify lines with beneficial traits.

In this paper the researchers, led by KAUST and including Dr Bettina Berger and Dr Chris Brien from the Australian Plant Phenomics Facility (APPF), use a functional data analysis approach to study the effects of salinity on growth patterns of barley grown at The Plant Accelerator® at the APPF. The method presented is suitable to reduce the noise in large-scale data sets and thereby increases the precision with which salinity tolerance can be measured.

Read the full paper, “Growth curve registration for evaluating salinity tolerance in barley” (DOI: 10.1186/s13007-017-0165-7) here.

Find out how the Australian Plant Phenomics Facility can support your plant science research here.

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High-throughput phenotyping at The Plant Accelerator®

 

 

Professor Mark Tester to talk plant science in Adelaide

Professor Mark Tester from King Abdullah University of Science & Technology (KAUST), Saudi Arabia, will present a talk in Adelaide this March:

“Into the field and into the genome – increasing salinity tolerance of crops”

Time:  Wednesday 8 March, 3.30pm – 4:30pm
Venue:  Hosted by The University of Adelaide, Plant Science Department, the talk will be held in the Plant Genomics Centre seminar room (Waite Campus, The University of Adelaide, South Australia) with drinks and nibbles afterwards. All are welcome.

About the speaker

Mark Tester is Professor of Bioscience at KAUST. After a PhD in Cambridge and lectureship there, he went to Adelaide, as a Research Professor in the Australian Centre for Plant Functional Genomics and Director of the Australian Plant Phenomics Facility. Mark was part of the team that led the establishment of this Facility, a $55m organisation that develops and delivers state-of-the-art phenotyping facilities, including The Plant Accelerator, an innovative plant growth and analysis facility. In his research group, forward and reverse genetic approaches are used to understand salinity tolerance and improve this in crops such as barley and tomatoes. His aspiration is to develop a new agricultural system where brackish water and seawater can be unlocked for food production.

Abstract

One-third of the world’s food is produced under irrigation, and this is directly threatened by over-exploitation of water resources and global environmental change. In this talk, the focus will be on the use of forward genetics to discover genes affecting salinity tolerance in barley, rice and tomatoes, along with some recent genomics in quinoa, a partially domesticated crop with high salinity tolerance. Rather than studying salinity tolerance as a trait in itself, we dissect salinity tolerance into a series of components that are hypothesised to contribute to overall salinity tolerance.

For barley, two consecutive years of field trials were conducted at the International Center for Biosaline Agriculture, a site with sandy soil and very low precipitation. Drip irrigation systems allowed the control of salinity by supplying plots with low (1 dS/m) and high salinity water (17 dS/m). A barley Nested Association Mapping (NAM) population developed by Klaus Pillen has been used to dissect physiologically and genetically complex traits in response to salt stress. Ten traits related to yield and yield components (e.g. days to flowering, harvest index, 100 seed mass) were recorded and five stress-indices were derived from each of these measurements. We have identified two significant loci located on the long arms of chromosomes 1H and 5H, which are both associated with several traits contributing to salinity tolerance, namely days to flowering, days to maturity, harvest index and yield.

For tomatoes, the focus is on genetics of tolerance in wild tomatoes, specifically Solanum galapagense, Solanum cheesmaniae and Solanum pimpinellifolium. An association genetic approach is being taken. High quality genome sequences have been made, and genotyping-by-sequencing undertaken. Tomatoes have been phenotyped in The Plant Accelerator and in the field, and analyses are currently in progress.

The application of this approach provides opportunities to significantly increase abiotic stress tolerance of crops, and thus contribute to increasing agricultural production in many regions.

Mark is in Adelaide between Mon 6th and Sun 12th March. If you would like to meet with Mark, please contact him directly: mark.tester@kaust.edu.sa

The Plant Accelerator

Plant phenotyping research projects facilitated by The Plant Accelerator vary from large scale screening of early growth, to salinity tolerance and water and nutrient use efficiency. Possible applications are diverse with respect to the measured traits and plant species studied. Please contact our experts to discuss how your research might benefit from the capabilities and services provided by The Plant Accelerator.

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The Plant Accelerator®,  Australian Plant Phenomics Facility, Adelaide, South Australia

Image-based phenotyping for non-destructive screening of different salinity tolerance traits in rice

Soil salinity is an abiotic stress wide spread in rice producing areas, limiting both plant growth and yield. The development of salt-tolerant rice requires efficient and high-throughput screening techniques to identify promising lines for salt affected areas. Advances made in image-based phenotyping techniques provide an opportunity to use non-destructive imaging to screen for salinity tolerance traits in a wide range of germplasm in a reliable, quantitative and efficient way. However, the application of image-based phenotyping in the development of salt-tolerant rice remains limited.

RiceJournalHairmansisA non-destructive image-based phenotyping protocol to assess salinity tolerance traits of two rice cultivars (IR64 and Fatmawati) has been established in this study. The response of rice to different levels of salt stress was quantified over time based on total shoot area and senescent shoot area, calculated from visible red-green-blue (RGB) and fluorescence images. The response of rice to salt stress (50, 75 and 100 mM NaCl) could be clearly distinguished from the control as indicated by the reduced increase of shoot area. The salt concentrations used had only a small effect on the growth of rice during the initial phase of stress, the shoot Na+ accumulation independent phase termed the ‘osmotic stress’ phase. However, after 20 d of treatment, the shoot area of salt stressed plants was reduced compared with non-stressed plants. This was accompanied by a significant increase in the concentration of Na+ in the shoot. Variation in the senescent area of the cultivars IR64 and Fatmawati in response to a high concentration of Na+ in the shoot indicates variation in tissue tolerance mechanisms between the cultivars.

Image analysis has the potential to be used for high-throughput screening procedures in the development of salt-tolerant rice. The ability of image analysis to discriminate between the different aspects of salt stress (shoot ion-independent stress and shoot ion dependent stress) makes it a useful tool for genetic and physiological studies to elucidate processes that contribute to salinity tolerance in rice. The technique has the potential for identifying the genetic basis of these mechanisms and assisting in pyramiding different tolerance mechanisms into breeding lines.

Publication:

Aris Hairmansis, Bettina Berger, Mark Tester and Stuart John Roy (Corresponding author)
Rice 2014, 7:16 doi:10.1186/s12284-014-0016-3  Published: 14 August 2014