A novel CO₂‐responsive systemic signaling pathway controlling plant mycorrhizal symbiosis

Abstract

Summary Elevated atmospheric carbon dioxide (eCO2) concentrations promote symbiosis between roots and arbuscular mycorrhizal fungi (AMF), modifying plant nutrient acquisition and cycling of carbon, nitrogen and phosphate. However, the biological mechanisms by which plants transmit aerial eCO2 cues to roots, to alter the symbiotic associations remain unknown. We used a range of interdisciplinary approaches, including gene silencing, grafting, transmission electron microscopy, liquid chromatography tandem mass spectrometry (LC–MS/MS), biochemical methodologies and gene transcript analysis to explore the complexities of environmental signal transmission from the point of perception in the leaves at the apex to the roots. Here we show that eCO2 triggers apoplastic hydrogen peroxide (H2O2)‐dependent auxin production in tomato shoots followed by systemic signaling that results in strigolactone biosynthesis in the roots. This redox‐auxin‐strigolactone systemic signaling cascade facilitates eCO2‐induced AMF symbiosis and phosphate utilization. Our results challenge the current paradigm of eCO2 effects on AMF and provide new insights into potential targets for manipulation of AMF symbiosis for high nutrient utilization under future climate change scenarios.

Auxin is involved in arbuscular mycorrhizal fungi-promoted tomato growth and NADP-malic enzymes expression in continuous cropping substrates

“…It has been shown that the inoculation of AMF can regulate hormone levels in plants [27,28]. In this study, the inoculation of AMF significantly increased IAA and CTK concentrations in tomato roots and significantly reduced ABA concentrations (Fig.…”

Physiological mechanism of strigolactone enhancing tolerance to low light stress in cucumber seedlings

“…It plays an important role in regulating plant branch growth, stem elongation, flowering, etc. [ 11 – 15 ] Strigolactone plays an important role in the redistribution of nitrogen in the aboveground tissues of plants. In addition, the content of nutrient elements in the plant growth environment can affect the overall structure of the plant, and the lack of nitrogen and phosphorus will cause plant roots to become elongated, with reduced branches [ 16 , 17 ].…”

Rapid systemic signaling during abiotic and biotic stresses: is the ROS wave master of all trades?

“…Recent studies and review articles proposed that systemic calcium, hydraulic, electric and ROS signals are interlinked (e.g. Gilroy et al , ; Choi et al , ; Zandalinas et al , ; Zhou et al , ; Devireddy et al , ). The calcium wave and the ROS wave were originally proposed to interact and amplify each other through the positive effects of calcium, directly or through calcium‐activated kinases, on ROS production by RBOHs, and the effect(s) of ROS on the opening or closing of calcium channels, directly or through ROS‐activated/suppressed kinases/phosphatases activity (Gilroy et al , ).…”

“…from the root to the shoot, or from lower leaves to upper leaves) or the downward (e.g. from the shoot to the root, or from upper leaves and/or flowering buds to lower leaves) direction (Suzuki et al , ; Gilroy et al , ; Gilroy et al , ; Guo et al , ; Choudhury et al , ; Lai et al , ; Wang et al , ; Zhou et al , ).…”