Carbon Monoxide Modulates Auxin Transport and Nitric Oxide Signaling in Plants under Iron Deficiency Stress

Carbon monoxide(CO)and nitric oxide(NO)are signal molecules that enhance plant adaptation to environmental stimuli.Auxin is an essential phytohormone for plant growth and development.CO and NO play crucial roles in modulating the plant’s response to iron deficiency.Iron deficiency leads to an increase in the activity of heme oxygenase(HO)and the subsequent generation of CO.Additionally,it alters the polar subcellular distribution of Pin-Formed 1(PIN1)proteins,resulting in enhanced auxin transport.This alteration,in turn,leads to an increase in NO accumulation.Furthermore,iron deficiency enhances the activity of ferric chelate reductase(FCR),as well as the expression of the Fer-like iron deficiency-induced transcription factor 1(FIT)and the ferric reduction oxidase 2(FRO2)genes in plant roots.Overexpression of the long hypocotyl 1(HY1)gene,which encodes heme oxygenase,or the CO donor treatment resulted in enhanced basipetal auxin transport,higher FCR activity,and the expression of FIT and FRO2 genes under Fe deficiency.Here,a potential mechanism is proposed:CO and NO interact with auxin to address iron deficiency stress.CO alters auxin transport,enhancing its accumulation in roots and up-regulating key iron-related genes like FRO2 and IRT1.Elevated auxin levels affect NO signaling,leading to greater sensitivity in root development.This interplay promotes FCR activity,which is crucial for iron absorption.Together,these molecules enhance iron uptake and root growth,revealing a novel aspect of plant physiology in adapting to environmental stress.

Identification and Transcriptional Regulation of CAMTA Genes in Liriodendron chinense

This study explores CAMTA genes in the rare and endangered Chinese plant species,Liriodendron chinense.Despite the completion of whole-genome sequencing,the roles of CAMTA genes in calcium regulation and stress responses in this species remain largely unexplored.Within the L.chinense genome,we identified two CAMTA genes,Lchi09764 and Lchi222536,characterized by four functional domains:CG-1,TIG,ANK repeats,and IQ motifs.Our analyses,including phylogenetic investigations,cis-regulatory element analyses,and chromosomal location studies,aim to elucidate the defining features of CAMTA genes in L.chinense.Applying Weighted Gene Co-Expression Network Analysis(WGCNA),we explored the impact of CAMTA genes on different organs and their regulation under abiotic stress conditions.The identification of significant gene modules and the prediction of promoter binding sites revealed co-expressed genes associated with CAMTA transcription factors.In summary,this study provides initial insights into CAMTA genes in L.chinense,laying the groundwork for future research on their evolution and biological roles.This knowledge enhancement contributes to a better understanding of plant responses to environmental stress—an essential aspect of plant biology.

Genome-wide identification and cold stress-induced expression analysis of the CBF gene family in Liriodendron chinense

Cold-resistance pathways that operate in model plants such as Arabidopsis thaliana and Oryza sativa have been studied extensively.It has been found that CBF genes play an important role in plant cold resistance.Liriodendron chinense,a tree known for its graceful tree shape and widely spread in south China,has weak cold tolerance.However,little is known about its response to cold.To further study the function of L.chinense CBF gene family,we started by characterizing all members of this gene family in the L.chinense genome and their expression profiling.Phylogenetic analysis found that 14 CBF genes in L.chinense are more closely related to their homologues in woody plants and A.thaliana than those in O.sativa.Cis-acting elements and GO analysis showed that some LcCBF genes participated in the biological process of cold stress response.The transcriptomic and RT-qPCR data showed that most of LcCBF genes displayed an initially increasing and subsequently decreasing trend during cold stress course and the expression profile of each member was different.Some LcCBF genes exhibited a different abundance in callus,root,stem and leaf tissues.The structure and expression characteristics of LcCBF genes imply that they may have similar and different functions in response to cold stress conditions.The identification and analysis of LcCBF gene family have laid the foundation for future studies into L.chinense cold stress mechanisms and for the cultivation of cold-resistance cultivars.