Roles of very long-chain fatty acids in compound leaf patterning inMedicago truncatula

Abstract

Plant cuticles are composed of hydrophobic cuticular waxes and cutin. Very long-chain fatty acids (VLCFAs) are components of epidermal waxes and the plasma membrane and are involved in organ morphogenesis. By screening a barrelclover (Medicago truncatula) mutant population tagged by the transposable element of tobacco (Nicotiana tabacum) cell type1 (Tnt1), we identified two types of mutants with unopened flower phenotypes, named unopened flower1 (uof1) and uof2. Both UOF1 and UOF2 encode enzymes that are involved in the biosynthesis of VLCFAs and cuticular wax. Comparative analysis of the mutants indicated that the mutation in UOF1, but not UOF2, leads to increased number of leaflets in M. truncatula. UOF1 was specifically expressed in the outermost cell layer (L1) of the shoot apical meristem (SAM) and leaf primordia. The uof1 mutants displayed defects in VLCFAs-mediated plasma membrane integrity, resulting in the disordered localization of the PIN-FORMED1 (PIN1) ortholog SMOOTH LEAF MARGIN1 (SLM1) in M. truncatula. Our work demonstrates that the UOF1-mediated biosynthesis of VLCFAs in L1 is critical for compound leaf patterning, which is associated with the polarization of the auxin efflux carrier in M. truncatula.

Late Elongated Hypocotyl Positively Regulates Salt Stress Tolerance in Medicago truncatula

“…The plant materials were ground into a fine powder using the Tissuelyser-48 (Shanghai Jingxin, Shanghai, China). Three biological samples were collected, and RT-qPCR analysis was conducted as described previously [ 45 ]. The UBQ gene was utilized as the internal reference, and all primers used are listed in Supplemental Table S1 .…”

The Ins and Outs of Homeodomain-Leucine Zipper/Hormone Networks in the Regulation of Plant Development

“…Epidermis-synthesized VLCFAs were shown to regulate cell proliferation in inner tissues—including SAM—by reducing CK biosynthesis in the vasculature [ 130 ]. Moreover, VCLFAs also control plasma membrane integrity, thus interfering with PIN1 polarity and, as a result, auxin distribution and organogenesis [ 131 , 132 ]. It is worth mentioning that VLCFA-containing ceramides were shown to stabilize ATML1 expression in the outer layer via its START domain, thus acting as a positional signal that sustains epidermal identity [ 37 ].…”

The role of Class Ⅱ KNOX family in controlling compound leaf patterning in Medicago truncatula

“…For transcriptomic analysis, the shoot buds were harvested from 30-d-old wild-type, mtknox4-1 mutant and 35Spro:YFP-MtKNOX4-1 plants. The transcriptomic assay was performed as previously described (Wang et al, 2023), and the heatmap was created by GraphPad Prism 8.0.…”