Preliminary Study Of Molecular Mechanism And Anatomic Structure Of Celery Leaf Development

Leaves are important vegetative organs in plants.The morphogenesis and spatial distribution of leaves have a great influence on the yield and quality of crops.Growth and development of plant leaves is affected by the genetic and environmental factors,and they have complex relationships.We have identified a number of genes and miRNAs that regulate leaf development,and preliminary illuminate and analyze their interaction.However,little is known about the molecular mechanism of leaf development in celery,which hinders the progress of studies on molecular mechanism of celery morphogenesis.Lignin is an important component of dietary fiber,and has a positive effect on improved health status since the consumption is related to decrease the risk of several diseases.Studies on the regulatory mechanisms of lignin biosynthesis and lignin distribution during celery leaf development may help to improve the quality of celery.Celery(Apium graveolens L.)belongs to the Apiaceae family and biennial herbs.The main eaten part of celery was leaves,such as petioles and leaf blades.The petioles and leaf blades at three stages of leaf growth and development were anatomically characterized with resin embedding with microtomy.From Stage 1 to Stage 3,the collenchyma and vascular bundles of the petioles and leaf blades developed to be thick and large,the phloem and xylem developed extensively,and the cells grew large and tightly arranged.The spongy and palisade mesophyll tissues were tightly arranged at the three stages.Transcriptome and small RNA libraries were constructed using leaves from three stages of celery cv.'Ventura'and then subjected to high-throughput sequencing and bioinformatics analysis.The abundance of genes and miRNAs related to leaf growth and development of the leaf blades and petioles at three leaf development stages were further analyzed.Results showed that they served important functions in regulating leaf development in celery.We also discussed the mechanism of lignin formation at different stages of celery development.Lignin accumulation in different tissues and at different stages of celery development coincides with the transcript levels of genes involved in lignin biosynthesis.This study contributes to our understanding on the molecular mechanism of celery leaf development,and may serve as a guide to develop breeding strategies that improve celery quality and yield.