Morphological and physiological effects of trans-cinnamic acid and its hydroxylated derivatives on maize root types

Abstract

Roots encounter cinnamic acid and its hydroxylated derivatives that are commonly found in soils. However, root systems consist of different root types with different morphological and physiological characteristics. Very little is known about the responses and adaptation mechanisms of the root types to cinnamic acid and its hydroxylated derivatives. In this study, the morphological and physiological responses of different maize root types exposed to different concentrations of t-cinnamic, ferulic, caffeic or p-coumaric acids were investigated. The results showed that the effects of allelochemicals were dependent on concentration, chemical structure, root type and process considered. In particular, t-cinnamic acid was characterized by higher allelopathic activity when compared with its derivatives, where a hydroxyl or methyl groups were present in aromatic ring. Among root types it was possible to delineate the following tolerance hierarchy: primary [ seminal [ nodal [ lateral of the primary = lateral of the seminal roots. Moreover, primary and seminal roots showed a different strategy to cope the chemical stress by either increasing or decreasing specific root length. Finally, an electrophysiological approach identified an involvement of proton pump activity and consequently a decrease in nitrate uptake.

Coumarin enhances nitrate uptake in maize roots through modulation of plasma membrane H+‐ATPase activity

“…) and more recently along the maize root axis (Lupini et al . ,b). The location of a 150‐kDa AtNAR2.1⁄AtNRT2.1 complex in PM of Arabidopsis roots seemed to confirm its functionality for high‐affinity nitrate influx (Yong et al .…”

“…; Lupini et al . ), sorgoleone, juglone and 2‐benzoxazolinone (BOA) (Friebe et al . ; Hejl & Koster ; Romero‐Romero et al .…”

“…The nutrient solution was renewed every 2 days (Lupini et al . ,b). Coumarin was purchased from Sigma‐Aldrich (St. Louis, MO, USA).…”

“…; Lupini et al . ). Negative effects of coumarin on cell division and root polarity in oat and Phleum pratense were previously reported (Goodwin & Avers ; Avers & Goodwin ).…”

Peer Review #1 of "Fine-root traits of allelopathic rice at the seedling stage and their relationship with allelopathic potential (v0.1)"

“…The fine-root traits were analyzed according to the procedure ofLupini et al (2016) andZhang, Fan &Wang (2018). Briefly, three plants of each rice cultivar were randomly selected for root analysis.…”