Non-destructive, whole-plant phenotyping reveals dynamic changes in water use efficiency, photosynthesis, and rhizosphere acidification of sorghum accessions under osmotic stress

Abstract

Noninvasive phenotyping can quantify dynamic plant growth processes at higher temporal resolution than destructive phenotyping and can reveal phenomena that would be missed by end-point analysis alone. Moreover, whole-plant phenotyping can identify germplasm and growth conditions that are optimal for both above- and below-ground tissues, and are important for efforts to breed more resilient and resource-efficient crops. However, noninvasive, dynamic phenotyping available today is generally expensive, complex, and non-modular. We developed a low-cost and versatile approach to non-invasively measure whole-plant performance over time by growing plants in isolated hydroponic chambers. We demonstrate the temporal and contextual versatility of our approach by measuring whole-plant biomass accumulation, water consumption, and water use efficiency every two days on unstressed and osmotically-stressed sorghum cultivars. In doing so, we identified relationships between root zone acidification and photosynthetic efficiency on whole-plant water use efficiency over time. Our system can be implemented using cheap, basic components and requires no specific technical expertise. It can, in theory, be used for any non-aquatic vascular plant species and for identifying more productive and resource-efficient crops.