scholarly journals A simple method for exogenously phytohormone application to the protodermal areas in the base of maize (Zea mays L.) leaf

Author(s):  
Jieping Li ◽  
Xinlei Feng

Abstract Background: The maize leaf epidermis is function as protection against water loss and gas exchange, contacting the environment and avoiding the damage, which is an attractive system for studying the process of cell fate and development. In monocots, leaves epidermis grown from basal meristem, which contains protodermal cells. The leaf protoderm zone was covered by the leaf sheath or coleoptile in maize, the classic exogenously phytohormone application method, such as spraying on leaf surface or adding in the culture media can’t apply the phytohormone to the protoderm areas directly, which restricts the research about phytohormone effect epidermal development.Results: Here we described a simple and direct method for exogenously application of phytohormone to maize leaf protoderm. We use the auxin analogs 2,4-D to test the system, and the asymmetrical division events which initial stomata development were decreased and the subsidiary cells were induced in advance after 2,4-D treatment. This result was the same as other similar studies’ results, indicated that the method is suitable for been used for application phytohormone to the maize leaf protodermal areas.Conclusions: The method, applied hormones on the mesocotyls of the maize seedlings, is simple and direct. Only a small amount of externally applied substances is required to complete this experiment through this method. The entire experiment process just last 10 days generally and it is easy to survey the phytohormone's effect on the epidermis development.

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Jieping Li ◽  
Xinlei Feng ◽  
Jinjin Xie

Abstract Background The leaf epidermis functions to prevent the loss of water and reduce gas exchange. As an interface between the plant and its external environment, it helps prevent damage, making it an attractive system for studying cell fate and development. In monocotyledons, the leaf epidermis grows from the basal meristem that contains protodermal cells. Leaf protoderm zone is covered by the leaf sheath or coleoptile in maize and wheat, preventing traditional exogenous phytohormone application methods, such as directly spraying on the leaf surface or indirectly via culture media, from reaching the protoderm areas directly. The lack of a suitable application method limits research on the effect of phytohormone on the development of grass epidermis. Results Here, we describe a direct and straightforward method to apply exogenous phytohormones to the leaf protoderms of maize and wheat. We used the auxin analogs 2,4-D and cytokinin analogs 6-BA to test the system. After 2,4-D treatment, the asymmetrical division events and initial stomata development were decreased, and the subsidiary cells were induced in maize, the number of GMC (guard mother cell), SMC (subsidiary mother cell) and young stomata were increased in wheat, and the size of the epidermal cells increased after 6-BA treatment in maize. Thus, the method is suitable for the application of phytohormone to the grass leaf protodermal areas. Conclusions The method to apply hormones to the mesocotyls of maize and wheat seedlings is simple and direct. Only a small amount of externally applied substances are needed to complete the procedure in this method. The entire experimental process lasts for ten days generally, and it is easy to evaluate the phytohormones’ effect on the epidermis development.


Development ◽  
1997 ◽  
Vol 124 (24) ◽  
pp. 5097-5106 ◽  
Author(s):  
G.J. Muehlbauer ◽  
J.E. Fowler ◽  
M. Freeling

The longitudinal axis of the maize leaf is composed of, in proximal to distal order, sheath, ligule, auricle and blade. The semidominant Liguleless3-O (Lg3-O) mutation disrupts leaf development at the ligular region of the leaf midrib by transforming blade to sheath. In a previous study, we showed that leaf sectors of Lg3 mutant activity are cell nonautonomous in the transverse dimension and can confer several alternative developmental fates (Fowler, Muehlbauer and Freeling (1996) Genetics 143, 489–503). In our present study we identify five Lg3 sector types in the leaf: sheath-like with displaced ligule (sheath-like), sheath-like with ectopic ligule (ectopic ligule), auricle-like, macro-hairless blade and wild-type blade. The acquisition of a specific sector fate depends on the timing of Lg3 expression. Early Lg3 expression results in adoption of the sheath-like phenotype at the ligule position (a proximal cell fate), whereas later Lg3 expression at the same position results in one of the more distal cell fates. Furthermore, sheath-like Lg3 sectors exhibit a graded continuum of phenotypes in the transformed blade region from the most proximal (sheath) to the most distal (wild-type blade), suggesting that cell fate acquisition is a gradual process. We propose a model for leaf cell fate acquisition based on a timing mechanism whereby cells of the leaf primordium progress through a maturation schedule of competency stages which eventually specify the cell types along the proximal to distal axis of the leaf. In addition, the lateral borders between Lg3 ‘on’ sectors and wild-type leaf sometimes provide evidence of no spreading of the transformed phenotype. In these cases, competency stages are inherited somatically.


2021 ◽  
Author(s):  
Christine Poon

AbstractArthroplasty implants e.g. hip, knee, spinal disc sustain relatively high compressive loading and friction wear, which lead to the formation of wear particles or debris between articulating surfaces. Despite advances in orthopaedic materials and surface treatments, the production of wear debris from any part of a joint arthroplasty implant is currently unavoidable. Implant wear debris induces host immune responses and inflammation, which causes patient pain and ultimately implant failure through progressive inflammation-mediated osteolysis and implant loosening, where the severity and rate of periprosthetic osteolysis depends on the material and physicochemical characteristics of the wear particles. Evaluating the cytotoxicity of implant wear particles is important for regulatory approved clinical application of arthroplasty implants, as is the study of cell-particle response pathways. However, the wear particles of polymeric materials commonly used for arthroplasty implants tend to float when placed in culture media, which limits their contact with cell cultures. This study reports a simple means of suspending wear particles in liquid medium using sodium carboxymethyl cellulose (NaCMC) to provide a more realistic proxy of the interaction between cells and tissues to wear particles in vivo, which are free-floating in synovial fluid within the joint cavity. Low concentrations of NaCMC dissolved in culture medium were found to be effective for suspending polymeric wear particles. Such suspensions may be used as more physiologically-relevant means for testing cellular responses to implant wear debris, as well as studying the combinative effects of shear and wear particle abrasion on cells in a dynamic culture environments such as perfused tissue-on-chip devices.


2019 ◽  
Vol 20 (10) ◽  
pp. 2472 ◽  
Author(s):  
Lei Dong ◽  
Lei Qin ◽  
Xiuru Dai ◽  
Zehong Ding ◽  
Ran Bi ◽  
...  

The morphological development of the leaf greatly influences plant architecture and crop yields. The maize leaf is composed of a leaf blade, ligule and sheath. Although extensive transcriptional profiling of the tissues along the longitudinal axis of the developing maize leaf blade has been conducted, little is known about the transcriptional dynamics in sheath tissues, which play important roles in supporting the leaf blade. Using a comprehensive transcriptome dataset, we demonstrated that the leaf sheath transcriptome dynamically changes during maturation, with the construction of basic cellular structures at the earliest stages of sheath maturation with a transition to cell wall biosynthesis and modifications. The transcriptome again changes with photosynthesis and lignin biosynthesis at the last stage of sheath tissue maturation. The different tissues of the maize leaf are highly specialized in their biological functions and we identified 15 genes expressed at significantly higher levels in the leaf sheath compared with their expression in the leaf blade, including the BOP2 homologs GRMZM2G026556 and GRMZM2G022606, DOGT1 (GRMZM2G403740) and transcription factors from the B3 domain, C2H2 zinc finger and homeobox gene families, implicating these genes in sheath maturation and organ specialization.


2015 ◽  
Vol 10 (3) ◽  
pp. e984531 ◽  
Author(s):  
Pantelis Livanos ◽  
Eleni Giannoutsou ◽  
Panagiotis Apostolakos ◽  
Basil Galatis

2001 ◽  
Vol 67 (10) ◽  
pp. 4858-4862 ◽  
Author(s):  
C. A. Fente ◽  
J. Jaimez Ordaz ◽  
B. I. Vázquez ◽  
C. M. Franco ◽  
A. Cepeda

ABSTRACT A new reliable, fast, and simple method for the detection of aflatoxigenic Aspergillus strains, consisting of the addition of a cyclodextrin (a methylated β-cyclodextrin derivative) to common media used for testing mycotoxin production ability, was developed. We propose the use of this compound as an additive for fungal culture media to enhance the natural fluorescence of aflatoxins. The production of aflatoxins coincided with the presence of a bright blue or blue-green fluorescent area surrounding colonies when observed under long-wavelength (365-nm) UV light after 3 days of incubation at 28°C. The presence of aflatoxins was confirmed by extracting the medium with chloroform and examining the extracts by high-pressure liquid chromatography with fluorescence detection.


Author(s):  
Mario S. Hoffman

A direct and simple method (YONAPAVE) for evaluating the structural needs of flexible pavements is presented. It is based on interpretation of measured falling-weight deflectometer (FWD) deflection basins using mechanistic and practical approaches. YONAPAVE estimates the effective structural number (SN) and the equivalent subgrade modulus independently of the pavement or layer thicknesses. Thus, there is no need to perform boreholes, which are expensive, time-consuming, and disruptive to traffic. Knowledge of the effective SN and the subgrade modulus together with an estimate of the traffic demand allows the determination of the overlay required to accommodate future needs. YONAPAVE’s simple equations can be solved using a pocket calculator, making it suitable for rapid estimates in the field. The simplicity of the method, and its independence from major computer programs, make YONAPAVE suitable for estimating the structural needs of a road network using FWD data collected on a routine or periodic basis along network roads. YONAPAVE can be used with increased experience and confidence as the basis for nondestructive testing structural evaluation and overlay design at the project level.


Development ◽  
2004 ◽  
Vol 131 (18) ◽  
pp. 4533-4544 ◽  
Author(s):  
M. T. Juarez

2000 ◽  
Vol 66 (11) ◽  
pp. 5024-5029 ◽  
Author(s):  
Luis A. Fernández ◽  
Isabel Sola ◽  
Luis Enjuanes ◽  
Víctor de Lorenzo

ABSTRACT A simple method for the nontoxic, specific, and efficient secretion of active single-chain Fv antibodies (scFvs) into the supernatants ofEscherichia coli cultures is reported. The method is based on the well-characterized hemolysin transport system (Hly) of E. coli that specifically secretes the target protein from the bacterial cytoplasm into the extracellular medium without a periplasmic intermediate. The culture media that accumulate these Hly-secreted scFv's can be used in a variety of immunoassays without purification. In addition, these culture supernatants are stable over long periods of time and can be handled basically as immune sera.


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