Monitoring the apical growth characteristics of hairy roots using non‐invasive laser speckle contrast imaging

Abstract

Hairy roots are used to produce plant agents and additives. Due to their heterogeneous structure and growth characteristics, it is difficult to determine growthrelated parameters continuously and in real time. Laser speckle contrast analysis is widely used as a non-destructive measurement technique in material testing or in medical technology. This type of analysis is based on the principle that moving objects or particles cause fluctuations in stochastic interference patterns known as speckle patterns. They are formed by the random backscattering of coherent laser light on an optically rough surface. A Laser Speckle Imager, which is well established for speckle studies of hemodynamics, was used for the first time for non-invasive speckle measurements on hairy roots to study dynamic behavior in plant tissue. Based on speckle contrast, a specific flux value was defined to map the dynamic changes in the investigated tissue. Using this method, we were able to predict the formation of lateral strands and to identify the growth zone in the apical root region, as well as dividing it into functional regions. This makes it possible to monitor physiological processes in the apical growth zone in vivo and in real time without labeling the target structures.

Effect of 10.6 μm laser moxibustion on inflammation in diabetic peripheral neuropathy rats

“…The infrared laser points were focused on the dorsal surface of the rats’ hind feet, and the blood perfusion volume of the rats’ skin was measured. Moor FLPI-2 measurement software V2.0 was used to record the data, and V5.0 software was used to process the laser speckle images and data ( 28 ). The final values are the average of both sides.…”

Label-free optical interferometric microscopy to characterize morphodynamics in living plants

“…In a recent study, the potential of biospeckle imaging has been shown in detection of endophytic colonization in leaves ( D’Jonsiles et al., 2020 ). The method has also been used to image bioactivity in the root and apical hairy root tissues ( Braga et al., 2009 ; Ribeiro et al., 2013 ; Schott et al., 2020 ; Schott et al., 2022 ). Figure 1C shows the biospeckle activity in heterogeneous hairy root culture in a cultivation assay over time.…”