scholarly journals Morphological Characterization and Transcriptome Analysis of New Dwarf and Narrow-Leaf (dnl2) Mutant in Maize

2022 ◽  
Vol 23 (2) ◽  
pp. 795
Author(s):  
Lulu Han ◽  
Chenggong Jiang ◽  
Wei Zhang ◽  
Hongwu Wang ◽  
Kun Li ◽  
...  

Lodging is the primary factor limiting high yield under a high plant density. However, an optimal plant height and leaf shape can effectively decrease the lodging risk. Here we studied an ethyl methanesulfonate (EMS)-induced dwarf and a narrow-leaf mutant, dnl2. Gene mapping indicated that the mutant was controlled by a gene located on chromosome nine. Phenotypic and cytological observations revealed that dnl2 showed inhibited cell growth, altered vascular bundle patterning, and disrupted secondary cell wall structure when compared with the wild-type, which could be the direct cause of the dwarf and narrow-leaf phenotype. The phytohormone levels, especially auxin and gibberellin, were significantly decreased in dnl2 compared to the wild-type plants. Transcriptome profiling of the internodes of the dnl2 mutant and wild-type revealed a large number of differentially expressed genes enriched in the cell wall biosynthesis, remodeling, and hormone biosynthesis and signaling pathways. Therefore, we suggest that crosstalk between hormones (the altered vascular bundle and secondary cell wall structure) may contribute to the dwarf and narrow-leaf phenotype by influencing cell growth. These results provide a foundation for DNL2 gene cloning and further elucidation of the molecular mechanism of the regulation of plant height and leaf shape in maize.

1952 ◽  
Vol 5 (2) ◽  
pp. 223 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell

The fine structure of the cell wall of both ray and vertical parenchyma has been investigated. In all species examined secondary thickening had occurred. In the primary cell wall the micellar orientation was approximately trans"erse to the longitudiJ)aI cell axis. Using optical and X-ray methods the secondary cell wall was shown to possess a helical micellar organization, the micelles being inclined between 30� and 60� to the longitudinal cell axis.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yongil Yang ◽  
Chang Geun Yoo ◽  
William Rottmann ◽  
Kimberly A. Winkeler ◽  
Cassandra M. Collins ◽  
...  

Abstract Background Plant secondary cell wall is a renewable feedstock for biofuels and biomaterials production. Arabidopsis VASCULAR-RELATED NAC DOMAIN (VND) has been demonstrated to be a key transcription factor regulating secondary cell wall biosynthesis. However, less is known about its role in the woody species. Results Here we report the functional characterization of Populus deltoides WOOD-ASSOCIATED NAC DOMAIN protein 3 (PdWND3A), a sequence homolog of Arabidopsis VND4 and VND5 that are members of transcription factor networks regulating secondary cell wall biosynthesis. PdWND3A was expressed at higher level in the xylem than in other tissues. The stem tissues of transgenic P. deltoides overexpressing PdWND3A (OXPdWND3A) contained more vessel cells than that of wild-type plants. Furthermore, lignin content and lignin monomer syringyl and guaiacyl (S/G) ratio were higher in OXPdWND3A transgenic plants than in wild-type plants. Consistent with these observations, the expression of FERULATE 5-HYDROXYLASE1 (F5H1), encoding an enzyme involved in the biosynthesis of sinapyl alcohol (S unit monolignol), was elevated in OXPdWND3A transgenic plants. Saccharification analysis indicated that the rate of sugar release was reduced in the transgenic plants. In addition, OXPdWND3A transgenic plants produced lower amounts of biomass than wild-type plants. Conclusions PdWND3A affects lignin biosynthesis and composition and negatively impacts sugar release and biomass production.


2020 ◽  
Author(s):  
Song Chen ◽  
Xin Lin ◽  
Xiyang Zhao ◽  
Su Chen

Abstract BackgroundCellulose is an essential structural component of plant cell wall and is an important resource to produce paper, textiles, bioplastics and other biomaterials. The synthesis of cellulose is among the most important but poorly understood biochemical processes, which is precisely regulated by internal and external cues.ResultsHere, we identified 46 gene models in 7 gene families which encoding cellulose synthase and related enzymes of Betula pendula, and the transcript abundance of these genes in xylem, root, leaf and flower tissues also be determined. Based on these RNA-seq data, we have identified 8 genes that most likely participate in secondary cell wall synthesis, which include 3 cellulose synthase genes and 5 cellulose synthase-like genes. In parallel, a gene co-expression network was also constructed based on transcriptome sequencing.ConclusionsIn this study, we have identified a total of 46 cell wall synthesis genes in B. pendula, which include 8 secondary cell wall synthesis genes. These analyses will help decipher the genetic information of the cell wall synthesis genes, elucidate the molecular mechanism of cellulose synthesis and understand the cell wall structure in B. pendula.


2021 ◽  
Vol 11 ◽  
Author(s):  
Ying Yu ◽  
Huizi Liu ◽  
Nan Zhang ◽  
Caiqiu Gao ◽  
Liwang Qi ◽  
...  

The MYB (v-myb avian myeloblastosis viral oncogene homolog) family is one of the largest transcription factor families in plants, and is widely involved in the regulation of plant metabolism. In this study, we show that a MYB4 transcription factor, BpMYB4, identified from birch (Betula platyphylla Suk.) and homologous to EgMYB1 from Eucalyptus robusta Smith and ZmMYB31 from Zea mays L. is involved in secondary cell wall synthesis. The expression level of BpMYB4 was higher in flowers relative to other tissues, and was induced by artificial bending and gravitational stimuli in developing xylem tissues. The expression of this gene was not enriched in the developing xylem during the active season, and showed higher transcript levels in xylem tissues around sprouting and near the dormant period. BpMYB4 also was induced express by abiotic stress. Functional analysis indicated that expression of BpMYB4 in transgenic Arabidopsis (Arabidopsis thaliana) plants could promote the growth of stems, and result in increased number of inflorescence stems and shoots. Anatomical observation of stem sections showed lower lignin deposition, and a chemical contents test also demonstrated increased cellulose and decreased lignin content in the transgenic plants. In addition, treatment with 100 mM NaCl and 200 mM mannitol resulted in the germination rate of the over-expressed lines being higher than that of the wild-type seeds. The proline content in transgenic plants was higher than that in WT, but MDA content was lower than that in WT. Further investigation in birch using transient transformation techniques indicated that overexpression of BpMYB4 could scavenge hydrogen peroxide and O2.– and reduce cell damage, compared with the wild-type plants. Therefore, we believe that BpMYB4 promotes stem development and cellulose biosynthesis as an inhibitor of lignin biosynthesis, and has a function in abiotic stress resistance.


2020 ◽  
Author(s):  
Suting Chen ◽  
Tianlu Teng ◽  
Shuan Wen ◽  
Tingting Zhang ◽  
Hairong Huang

Abstract Background: The integrity of cell wall structure is highly significant for the in vivo survival for mycobacteria. However, the mechanisms underlying the biosynthesis of mycobacterial cell wall remain poorly understood. aceE encodes the E1 component of pyruvate dehydrogenase (PDH)complex. This study aimed to know the functional role of aceE gene in cell wall biosynthesis in M. smegmatis.Results: We observed that the colony morphology of aceE-deficient mutants(aceE-mut)was quite different from the wild-type(WT) strain during the transposon library screening of M.smegmatis, smaller and smoother on the solid culture medium. Notably, the aceE-mut lost its ability of growing aggregately and biofilm forming, which are two very important features of mycobacteria.The morphological changes of the aceE-mut strain were further confirmed by electron microscopy that presented shorter, smoother and thinner images in contrast withWT strain.Additionally, the analysis of mycolic acid(MA)using LC-MS indicated deficiency of alpha-MA and epoxy-MA in aceE-mut strain whereas complementation of the aceE-mut with a wild-type aceEgene restored the composition of MA. Conclusions: Overall, this study indicates that aceE gene plays a significant role in the mycolic acid synthesis and affects the colony morphology and biofilm formation of M.smegmatis.


2000 ◽  
Vol 355 (1398) ◽  
pp. 857-868 ◽  
Author(s):  
William E. Friedman ◽  
Martha E. Cook

Although there is clear evidence for the establishment of terrestrial plant life by the end of the Ordovician, the fossil record indicates that land plants remained extremely small and structurally simple until the Late Silurian. Among the events associated with this first major radiation of land plants is the evolution of tracheids, complex water–conducting cells defined by the presence of lignified secondary cell wall thickenings. Recent palaeobotanical analyses indicate that Early Devonian tracheids appear to possess secondary cell wall thickenings composed of two distinct layers: a degradation–prone layer adjacent to the primary cell wall and a degradation–resistant (possibly lignified) layer next to the cell lumen. In order to understand better the early evolution of tracheids, developmental and comparative studies of key basal (and potentially plesiomorphic) extant vascular plants have been initiated. Ultra–structural analysis and enzyme degradation studies of wall structure (to approximate diagenetic alterations of fossil tracheid structure) have been conducted on basal members of each of the two major clades of extant vascular plants: Huperzia (Lycophytina) and Equisetum (Euphyllophytina). This research demonstrates that secondary cell walls of extant basal vascular plants include a degradation–prone layer (‘template layer’) and a degradation–resistant layer (‘resistant layer’). This pattern of secondary cell wall formation in the water–conducting cells of extant vascular plants matches the pattern of wall thickenings in the tracheids of early fossil vascular plants and provides a key evolutionary link between tracheids of living vascular plants and those of their earliest fossil ancestors. Further studies of tracheid development and structure among basal extant vascular plants will lead to a more precise reconstruction of the early evolution of water–conducting tissues in land plants, and will add to the current limited knowledge of spatial, temporal and cytochemical aspects of cell wall formation in tracheary elements of vascular plants.


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