Functional Study Of The New Member CARF,which Of The PXY Signaling Pathway Involved In Vascular Development

Through the vascular cambium cell division and differentiation,the older cells of plants moved to the meristem of both sides,usually forming primary phloem outwards and forming primary xylem inwards,and with the formation of cambium between beam and cyclization and transferred to secondary gro WTh phase,namely through the vascular cambium cell division and differentiation to form secondary phloem and secondary xylem.Vascular meristem is responsible for most plant biomass,it is mainly composed of xylem,because the secondary xylem has a large number of secondary cell wall,the wood tissue represents the enormous energy and renewable biomass resources.In arabidopsis thaliana vascular development related studies,the most widely understanding in current is TDIF-PXY/TDR-WOX4/WOX14 signaling pathways.On the one hand,promoting the formation of layer-added value through the redundant regulation of WOX4 and WOX14.On the other hand,inhibits xylem differentiation through the GSK3 protein family.In addition to the well-known cambium the regulation of proliferation and differentiation of signaling pathways,there are other CLE peptide and receptor protein kinase(LRR-RLK)involved in the development of vascular cambium,this topic is mainly to explore some relation between them from two aspects,the receptor PXY two homologous genes,PXL3?PXL4 and ligand CARF.On the one hand,by infecting WT?pxy?pxl3pxl4?pxypxl3pxl4 these four kinds of plants through CARF overexpression,to explore influences on vascular development in arabidopsis thaliana plants by increasing the expression of CARF.The effect of CARF expression on vascular development was obvious observed that in the four plant backgrounds of WT?pxy?pxl3pxl4 and pxypxl3pxl4,increasing the expression of CARF will result in the whole gro WTh of the plant.From the plant height and root length,it can be seen that the whole plant exhibits a gro WTh inhibiting phenotype.Under the background of WT and pxy,the plants became shorter,the root length became shorter,the accumulation of anthocyanins on the back of rosette leaves occurred,the overall gro WTh weakened,and the phenotype was the most obvious under the background of pxl3pxl4 and pxypxl3pxl4.Not only the above phenotype,and more significant phenotypes appeared in 6-week-old plants and the rosette phenotype was abruptly increased.All of these plants had obvious abortion and seed hypoplasia,and from the Arabidopsis seedlings in the 2-week background of pxl3pxl4 and pxypxl3pxl4,one can see the special situation in which apical meristem development has been restricted.On the other hand,to verify the previous experimental results by adding peptides in vitro.First,four Arabidopsis thaliana plants,WT?pxy?pxl3pxl4 and pxypxl3pxl4,were treated by adding different concentrations of CARF_Pand CARF_P-P9A peptides in vitro.Then observed the changes of hypocotyl column cells within 10 days and found that the number of column cells increased with increasing concentrations of CARF_Pin WT?pxl3pxl4 background,especially pxl3pxl4,showed about 7 times the number of column cells under 100?M CARF_P,and its sensitivity to CARF_Pwas very high as well.The cell polarity was obscured at 0.1?M,but pxy?pxypxl3pxl4 did not change significantly under CARF_Ppeptide treatment.Second,CARF_Pand CARF_P-P9A peptides treated WT?pxy?pxl3pxl4?pxypxl3pxl4 Arabidopsis plant10-day roots and found that CARF_Ppeptide treated WT?pxy?pxl3pxl4?pxypxl3pxl4generally shorter root length.Finally,10?M CARF_Pand CARF_P-P9A peptides were treated in vitro with WT?pxy?pxl3pxl4?pxypxl3pxl4 six-week-old Arabidopsis plants,CARF_Pwas found overall inhibit plant height and root length,CARF_Ppeptide can also promote plant rosette leaves except for pxy,in terms of cell gro WTh,CARF_Ppeptides will reduce WT and pxl3pxl4 xylem cells reduce lignification degree,and in the whole experiment CARF_P-P9A peptides processing did not cause significant change.These two aspects illustrated the effect of CARF on vascular development,and also confirmed the relationship between CARF and PXY?PXL3 and PXL4.