Molecular analysis of SCARECROW function reveals a radial patterning mechanism common to root and shoot

Development ◽  
2000 ◽  
Vol 127 (3) ◽  
pp. 595-603 ◽  
Author(s):  
J.W. Wysocka-Diller ◽  
Y. Helariutta ◽  
H. Fukaki ◽  
J.E. Malamy ◽  
P.N. Benfey
Keyword(s):  
Bundle Sheath ◽  
Quiescent Center ◽  
Ground Tissue ◽  
Tissue Layer ◽  
Radial Pattern ◽  
Radial Patterning ◽  
Bundle Sheath Cells ◽  
Root Analysis ◽  
Tight Correlation ◽  
Embryonic Root

Mutation of the SCARECROW (SCR) gene results in a radial pattern defect, loss of a ground tissue layer, in the root. Analysis of the shoot phenotype of scr mutants revealed that both hypocotyl and shoot inflorescence also have a radial pattern defect, loss of a normal starch sheath layer, and consequently are unable to sense gravity in the shoot. Analogous to its expression in the endodermis of the root, SCR is expressed in the starch sheath of the hypocotyl and inflorescence stem. The SCR expression pattern in leaf bundle sheath cells and root quiescent center cells led to the identification of additional phenotypic defects in these tissues. SCR expression in a pin-formed mutant background suggested the possible origins of the starch sheath in the shoot inflorescence. Analysis of SCR expression and the mutant phenotype from the earliest stages of embryogenesis revealed a tight correlation between defective cell divisions and SCR expression in cells that contribute to ground tissue radial patterning in both embryonic root and shoot. Our data provides evidence that the same molecular mechanism regulates the radial patterning of ground tissue in both root and shoot during embryogenesis as well as postembryonically.

scholarly journals ROOT PATTERNING AND REGENERATION ARE MEDIATED BY THE QUIESCENT CENTER AND INVOLVE BLUEJAY, JACKDAW AND SCARECROW REGULATION OF VASCULATURE FACTORS

2019 ◽  
Author(s):  
Alvaro Sanchez-Corrionero ◽  
Pablo Perez-Garcia ◽  
Javier Cabrera ◽  
Javier Silva-Navas ◽  
Juan Perianez-Rodriguez ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Postembryonic Development ◽  
Quiescent Center ◽  
Ground Tissue ◽  
Short Root ◽  
Cell Lineages ◽  
Radial Patterning ◽  
Severe Impairment

ABSTRACTStem cells are central to plant development. During root postembryonic development stem cells generating tissues are patterned in layers around a stem cell organizer or quiescent center (QC). How stem cell lineages are initially patterned is unclear. Here, we describe a role for BLUEJAY (BLJ), JACKDAW (JKD) and SCARECROW (SCR) transcription factors in patterning of cell lineages during growth and in patterning reestablishment during regeneration through regulation of number of QC cells and their regenerative capacities. In blj jkd scr mutants, QC cells are progressively lost which results in loss of tissue layers. Upon laser ablation blj jkd scr is impaired in QC division and specification resulting in severe impairment in pattern regeneration. Beyond direct regulation of QC activity by these transcription factors, reduced levels of SHORT-ROOT (SHR) and of PIN auxin transporters were observed in the vasculature of blj jkd scr, leading to strong reduction in the auxin response in the QC. We narrowed down non-cell-autonomous regulation of vascularly expressed genes in blj jkd scr to C-REPEAT BINDING FACTOR 3 (CBF3). cbf3 mutant shows reduced levels of SHR in the vasculature, and in addition QC disorganization and downregulation of the QC regulator WUSCHEL-RELATED HOMEODOMAIN 5 (WOX5). CBF3 gene is primarily expressed in the ground tissue downstream of BLJ, JKD and SCR, while CBF3 protein may move. Targeted-expression of CBF3 to the ground tissue of blj jkd scr recovers radial patterning and regeneration. We propose that BLJ, JKD and SCR regulate QC-mediated patterning, and that part of this regulation involves CBF3.

scholarly journals Transmission of Engineered Plastids in Sugarcane, a C4 Monocotyledonous Plant, Reveals that Sorting of Preprogrammed Progenitor Cells Produce Heteroplasmy

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 26
Author(s):  
Ghulam Mustafa ◽  
Muhammad Sarwar Khan
Keyword(s):  
Progenitor Cells ◽  
Plastid Transformation ◽  
Bundle Sheath ◽  
Homologous Sequence ◽  
Regeneration System ◽  
Mesophyll Cells ◽  
Transgenic Sugarcane ◽  
Bundle Sheath Cells ◽  
Dicotyledonous Plants ◽  
Species Specific

We report here plastid transformation in sugarcane using biolistic transformation and embryogenesis-based regeneration approaches. Somatic embryos were developed from unfurled leaf sections, containing preprogrammed progenitor cells, to recover transformation events on antibiotic-containing regeneration medium. After developing a proficient regeneration system, the FLARE-S (fluorescent antibiotic resistance enzyme, spectinomycin and streptomycin) expression cassette that carries species-specific homologous sequence tails was used to transform plastids and track gene transmission and expression in sugarcane. Plants regenerated from streptomycin-resistant and genetically confirmed shoots were subjected to visual detection of the fluorescent enzyme using a fluorescent stereomicroscope, after genetic confirmation. The resultant heteroplasmic shoots remained to segregate on streptomycin-containing MS medium, referring to the unique pattern of division and sorting of cells in C4 monocotyledonous compared to C3 monocotyledonous and dicotyledonous plants since in sugarcane bundle sheath and mesophyll cells are distinct and sort independently after division. Hence, the transformation of either mesophyll or bundle sheath cells will develop heteroplasmic transgenic plants, suggesting the transformation of both types of cells. Whilst developed transgenic sugarcane plants are heteroplasmic, and selection-based regeneration protocol envisaging the role of division and sorting of cells in the purification of transplastomic demands further improvement, the study has established many parameters that may open up exciting possibilities to express genes of agricultural or pharmaceutical importance in sugarcane.

Estimation of diffusive resistance of bundle sheath cells to CO2 from modeling of C4 photosynthesis

1996 ◽  
Vol 49 (3) ◽  
pp. 195-208 ◽  
Author(s):  
Dongxiang He ◽  
Gerald E. Edwards
Keyword(s):  
C4 Photosynthesis ◽  
Bundle Sheath ◽  
Diffusive Resistance ◽  
Bundle Sheath Cells ◽  
Sheath Cells

Nitrate metabolism in relation to the aspartate-type C-4 pathway of photosynthesis in Eleusine coracana

1974 ◽  
Vol 52 (12) ◽  
pp. 2599-2605 ◽  
Author(s):  
C. K. M. Rathnam ◽  
V. S. R. Das
Keyword(s):  
Glutamate Dehydrogenase ◽  
Eleusine Coracana ◽  
Bundle Sheath ◽  
Chloroplast Envelope ◽  
Mesophyll Cells ◽  
Bundle Sheath Cells ◽  
Nitrate Metabolism ◽  
Type C ◽  
Envelope Membranes ◽  
Sheath Cells

The intercellular and intracellular distributions of nitrate assimilating enzymes were studied. Nitrate reductase was found to be localized on the chloroplast envelope membranes. The chloroplastic NADPH – glutamate dehydrogenase was concentrated in the mesophyll cells. The extrachloroplastic NADH – glutamate dehydrogenase was localized in the bundle sheath cells. Glutamate synthesized in the mesophyll chloroplasts was interpreted to be utilized exclusively in the synthesis of aspartate, while in the bundle sheath cells it was thought to be consumed in other cellular metabolic processes. Based on the results, a scheme is proposed to account for the nitrate metabolism in the leaves of Eleusine coracana Gaertn. in relation to its aspartate-type C-4 pathway of photosynthesis.

scholarly journals Transient expression from cab-m1 and rbcS-m3 promoter sequences is different in mesophyll and bundle sheath cells in maize leaves.

1992 ◽  
Vol 89 (8) ◽  
pp. 3654-3658 ◽  
Author(s):  
K. C. Bansal ◽  
J. F. Viret ◽  
J. Haley ◽  
B. M. Khan ◽  
R. Schantz ◽  
...  
Keyword(s):  
Transient Expression ◽  
Bundle Sheath ◽  
Promoter Sequences ◽  
Bundle Sheath Cells ◽  
Maize Leaves ◽  
Sheath Cells
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