The microstructure investigation of plant architecture with X-ray microscopy

Abstract

18Background 19 In recent years, the plant morphology has been well studied by multiple approaches at 20 cellular and subcellular levels. Two-dimensional (2D) microscopy techniques offer 21 imaging of plant structures on a wide range of magnifications for researchers. However, 22 subcellular imaging is still challenging in plant tissues like roots and seeds. 23 Results 24Here we use a three-dimensional (3D) imaging technology based on the ZEISS X-ray 25 microscope (XRM) Versa and analyze several plant tissues from different plant species. 26 The XRM provides new insights into plant structures using non-destructive imaging at 27 high-resolution and high contrast. We also developed a workflow aiming to acquire 28 accurate and high-quality images in the context of the whole specimen. Multiple plant 29 samples including rice, tobacco, Arabidopsis and maize were used to display the 30 differences of phenotypes, which indicates that the XRM is a powerful tool to 31 investigate plant microstructure. 32 Conclusions 33 Our work provides a novel observation method to evaluate and quantify tissue specific 34 differences for a range of plant species. This new tool is suitable for non-destructive 35 seed observation and screening. 36 37 Keywords: X-ray microscopy, plant morphology, plant development, plant 3D 38 reconstruction 39 Background 40 Since the invention and development of microscopes, it has extended human vision 41 substantially. The observation of cellular and subcellular structures using microscopes 42 have broadened our knowledge to understand the biological world more efficiently [1]. 43 ZEISS and many other microscopy manufacturing companies are spending an 44 enormous amount of time and resources developing higher resolution microscopy 45 systems to assist scientists acquire more detailed images in their research fields. From 46 the single cell organism blue-green algae (Cyanobacteria) to over a hundred-meter-tall 47 giant tree (Eucalyptus regnans), plants display versatile morphologies to survive in 48 different environments. Therefore, utilizing microscopy techniques to study the cellular 49 and subcellular and physiological traits is essential in plant research.50 51 In the 21 st century, microscopy companies provide a variety of measurement techniques 52 for scientists. With the assistance of electron microscopy, plant scientists can observe 53 the cell surface and the detailed structure of organelles, and even decipher the structure 54 of proteins [2-4]. Optical microscopes, including upright and inverted microscopes, 55 provide powerful solutions for cellular observations as well [5, 6]. Since the application 56 of green fluorescent protein, confocal microscopy and various fluorescence related 57 techniques advanced the biological research field [7]. Furthermore, the methods to 58 analyze the corresponding data have been developed at a similar pace [8]. For larger 59 sample observation, stereoscopic microscopy offers non-destructive and detailed 60 insights to identify the tiny differences in betw...