Long‐distance communication through systemic macromolecular signaling mediates stress defense responses in plants

Abstract

Land plants have a unique vascular bundle system that ranges in length from a few centimeters to hundreds of meters. These systems integrate the various organs of the whole plant, perform material exchange between different plant tissues and mediate the transmission of signals between cells or over long distances. Grafting and parasitism can reshape the vascular tissues of different ecotypes or species and represent two important systems for studying plant systemic signaling. In recent years, with the advancement of genomics and sequencing technology, the transportation, identification, and function of systemic plant macromolecules have been extensively studied. Here, we review the current body of knowledge of the transport pathways and regulatory mechanisms of macromolecules in plants and assess systemic, long‐distance signal trafficking that mediates stress responses, and plant–environment or plant–insect community interactions. Additionally, we propose several methods for identifying mobile mRNAs and proteins. Finally, we discuss the challenges facing systemic signaling research and put forth the most urgent questions that need to be answered to advance our understanding of plant systemic signaling.

Transcriptome analysis reveals the effect of grafting on gossypol biosynthesis and gland formation in cotton

“…The gene expression in the high-gossypol cotton is affected by the low-gossypol cotton and is significantly down-regulated. The interaction between rootstock and scion also appeared in previous studies, such as Arabidopsis thaliana [ 49 ], potato [ 50 ], grape [ 51 ], etc., and this phenomenon may be caused by the mutual movement of some biological macromolecules between the two parts [ 52 , 53 ]. Therefore, we speculate that high-gossypol cotton may transmit certain signaling molecules through the conduit, thereby stimulating the expression of gossypol synthesis-related genes in low-gossypol cotton.…”

Transport of Nanoparticles into Plants and Their Detection Methods

“…This natural transport system within the stem is well adapted to carry and distribute larger particles efficiently. The stem’s vascular system is responsible for the long-distance transport of water and nutrients from the roots to the leaves and other plant parts [ 223 ]. It is capable of maintaining the flow of materials over significant distances, making it an ideal route for distributing larger particles throughout the plant.…”

Root osmotic sensing from local perception to systemic responses

“…Breakthroughs studies on the regulatory mechanisms of long-distance RNA transport have been made in recent years. For detailed reviews of RNA trafficking see the publications of Ham and Lucas ( 2017 ); Kehr and Kragler ( 2018 ); Liu and Chen ( 2018 ) or Zhang et al ( 2021a , b ). While the existence of mRNAs and ncRNAs in the vascular system hints at their mobility and possible role, identification alone does not conclusively prove movement or physiological function.…”

“…While the existence of mRNAs and ncRNAs in the vascular system hints at their mobility and possible role, identification alone does not conclusively prove movement or physiological function. By using homo (intra species) and hetero (inter species) grafting, many studies in model plants, crops and woody plants have provided evidence for mobile mRNAs (Notaguchi et al 2015 , Thieme et al 2015 , Liu et al ( 2020 ) and lnRNA (Zhang et al 2009 ; Zhang et al 2021a , b ). Similar results were also reported for miRNAs (Pagliarani et al 2017 ; Tolstyko et al 2019 ).…”