Fig 1.
Dominant negative inhibition of particulate trafficking in N. benthamiana leaf epidermal cells upon transient overexpression of β-glucuronidase (GUS; control), the globular tail domain of N. benthamiana myosin XI-K (XI-K GTD) and the myosin-binding DUF593 domains of N. benthamiana MyoB1 and MyoB2 (MyoB1 DUF593 and MyoB2 DUF593).
The mean velocities (μm/sec) and standard deviations are shown for MyoB1 compartment tagged by full-size N. benthamiana MyoB1-GFP (A), Golgi stacks (B), mitochondria (C), peroxisomes (D), vesicles tagged by mCherry:VAMP721 (E) and inclusion bodies formed by the C-terminal fragment of mCherry-tagged, viral proteinμNS, mCherry-μNS (F). Percent of the mean velocity reduction relative to GUS control is shown below each column.
Fig 2.
Velocity distribution profiles for organelles, VAMP721 vesicles, mCherry- μNS inclusion bodies, and MyoB1-GFP vesicle-like bodies in the presence of GUS (see legend to Fig 1).
Distributions were plotted as % of objects exhibiting velocity range that falls in each bin of 0.5 μm/sec width.
Fig 3.
Size analysis of the leaf mesophyll and leaf midvein epidermal cells of the synthetic quintuple mutant Arabidopsis lines xi-k xi-1 myob1-3 and xi-k xi-2 myob1-3 compared to Columbia and parental lines myob1-3, xi-k xi-1 and xi-k xi-2.
Red asterisks indicate highly statistically significant differences (p<0.001) between each of the quintuple mutant line on one hand, and each of the corresponding control lines. (A) Mean diameters and standard deviations of the leaf mesophyll cells. (B) Mean lengths and standard deviations of the epidermal cells. (C and D) Representative images of the mesophyll and epidermal cells, respectively, of the Columbia and xi-k xi-2 myob1-3 plant lines. Note apparently normal cell morphology in the quintuple mutant lines.
Fig 4.
Growth phenotypes of the synthetic quintuple mutant Arabidopsis lines xi-k xi-1 myob1-3 and xi-k xi-2 myob1-3 compared to Columbia and parental lines myob1-3, xi-k xi-1 and xi-k xi-2.
Red asterisks, same as in Fig 3. (A) Mean plant heights and standard deviations. (B) Mean leaf rosette spans and standard deviations.
Fig 5.
Representative images of the synthetic quintuple mutant Arabidopsis plants xi-k xi-1 myob1-3 and xi-k xi-2 myob1-3 compared to Columbia and parental lines myob1-3, xi-k xi-1 and xi-k xi-2 at 7 weeks after sawing.
(A) The stems with siliques and flowers; note irregular stem shape in quintuple mutant plants. (B) Fragments of the stems with siliques; note irregular orientation of siliques relative to stems and misshaped silique stalks. (C) Leaf rosettes (stems and roots were cut off).
Fig 6.
Mean flowering time and standard deviations for the synthetic quintuple mutant Arabidopsis lines xi-k xi-1 myob1-3 and xi-k xi-2 myob1-3 compared to Columbia and parental lines myob1-3, xi-k xi-1 and xi-k xi-2.
Black asterisk indicates marginally statistically significant difference (p = 0.05) between the xi-k xi-2 myob1-3 and a corresponding xi-k xi-2 control (the difference between this s5KO and Columbia or myob1-3 controls was highly significant at p<0.001).
Fig 7.
Model of two major particle trafficking mechanisms in plant cells.
The active, myosin-driven transport of the MyoB membrane compartment along the F-actin bundles entrains cytosolic flow, which carries various organelles, vesicles and inert tracer mCherry-μNS bodies.