Timing matters: Exudates collection duration impacts tomato root exudome under nutrient deficiencies

Abstract

Plants rely on their root system to retrieve nutrients from the rhizosphere. Root exudation is recognized as a crucial plant adaptation to facilitate their acquisition. Hydroponic-only systems are among the most diffused approaches to sample and study root exudates. However, the extent to which experimental factors, such as exudate collection duration, might mask the impact of abiotic stress such as nutrient deficiencies on root exudation remains uncertain.Our results show that the duration of exudate collection has a great impact on the exudation dynamics of tomato plants grown under nutrient deficiencies. Hence, an inappropriate choice of the exudates collection duration will prevent an accurate identification of the differences in root exudates dynamics when plants are grown under varying nutrient statuses. We therefore recommend running pre-experiments to define the optimal duration of exudates collection for each specific experimental setup, to acquire reliable and representative data on root exudation.