A Thermoacoustic Imaging System for Noninvasive and Nondestructive Root Phenotyping

Abstract

Information about the root system architecture of plants is of great value in modern crop science. However, there is a dearth of tools that can provide field-scale measurements of below-ground parameters in a non-destructive and non-invasive fashion. In this paper, we propose a multi-modal, non-contact thermoacoustic sensing system to address this measurement gap and discuss various system design aspects in the context of belowground sensing. We also demonstrate the first thermoacoustic images of plant material (potatoes) in a soil medium, with the use of highly sensitive capacitive micromachined ultrasound transducers enabling non-contact detection and cm-scale image resolution. Finally, we show high correlation (adj. R 2 = 0.95) between the measured biomass content and the reconstructed thermoacoustic images of the potato tubers.

Genetic Circuit Design in Rhizobacteria

“…Additionally, their gas reporter approach appears compatible with existing infrastructure used to study plant release/uptake of gaseous compounds [212]. Ultrasound technology for imaging soil-grown plant roots [213] might similarly be adapted to detect acoustic reporters (i.e., gasfilled protein nanostructures) produced by rhizosphere bacteria [214]. While functioning of these reporters has yet to be demonstrated in rhizobacterial species, they have shown promise for in situ reporting within the mammalian microbiome [215].…”

LEADER (Leaf Element Accumulation from DEep Roots): A nondestructive phenotyping platform to estimate rooting depth in the field

“…Ground penetrating radar (GPR) is being used for coarse roots of trees (Alani & Lantini, 2020; Hruska et al., 1999) and has agronomic applications to the coarser roots of root and tuber crops (Delgado et al., 2017; Guo et al., 2013; Wu et al., 2014) but is not yet capable of detecting fine roots, which are responsible for the majority of water and nutrient acqusition. New indirect methods include electrical impedance spectroscopy (Peruzzo et al., 2021), in‐field MRI (Bagnall et al., 2020), thermoacoustic imaging (Singhvi et al., 2022), ultra‐wideband microwave imaging (Shi et al., 2022), and electrical resistance tomography (Srayeddin & Doussan, 2009; Whalley et al., 2017), though all of these technologies are emerging. They are also depth limited based on the probe size and may not work in all soils.…”