Abstract
BackgroundThe adventitious roots (AR) of plants share the same function as primary and lateral roots (LR), although their development is mainly an adaptive reaction to stress conditions. Regeneration of grafted plants is often accompanied by AR formation thus making the grafting technique a good model for studying AR initiation and development and their means of emergence. Pectins and arabinogalactan proteins (AGP) are helpful markers of particular cellular events, such as programmed cell death (PCD), elongation, proliferation or other differentiation events that accompany AR development. However, little is known about the distribution of pectins and AGPs during AR ontogeny, either in the primordium or stem tissues from which AR arise or their correspondence with these events during LR formation.ResultsAR were developed from different stem tissues such as parenchyma, xylem rays and the cambium, depending on the stem age and treatment (grafting versus cutting) of the parental tissue. Immunochemical analysis of the presence of pectic (LM8, LM19, LM20) and AGP (JIM8, JIM13, JIM16) epitopes in AR and AR-associated tissues showed differential, tissue-specific distributions of these epitopes. Two pectic epitopes (LM19, LM20) were developmentally regulated and the occurrence of the LM8 xylogalacturonan epitope in the root cap of the AR differed from other species described so far. AGP epitopes were abundantly present in the cytoplasmic compartments (mainly the tonoplast) and were correlated with the degree of cell vacuolisation. JIM8 and JIM13 epitopes were detected in the more advanced stages of primordium development, whereas the JIM16 epitope was present from the earliest division events of the initial AR cells. The comparison between AR and LR showed quantitative (AGP,) and qualitative (pectins) differences.ConclusionThe chemical compositions of adventitious and lateral root cells show differences that correlate with the different origins of these cells. In AR, developmental changes in the distribution of pectins and AGP suggest the turnover of wall compounds. Our data extend the knowledge about the distribution of pectin and AGP during non-embryogenic root development in a species that is important from an agronomic point of view.
Highlights
The adventitious roots (AR) of plants share the same function as primary and lateral roots (LR), their development is mainly an adaptive reaction to stress conditions
Among the various cellular events that are triggered by grafting, we focused on AR development with particular emphasis on the distribution of the pectic and Arabinogalactan proteins (AGPs) epitopes during this process in both the AR and the scion tissues surrounding the developing AR
Adventitious roots – morphology The AR that originate from tomato stems emerge in three different ways (I, II, III), depending on the stage of stem development and the type of procedure that is used to induce their growth (Fig. 1)
Summary
The adventitious roots (AR) of plants share the same function as primary and lateral roots (LR), their development is mainly an adaptive reaction to stress conditions. Pectins and arabinogalactan proteins (AGP) are helpful markers of particular cellular events, such as programmed cell death (PCD), elongation, proliferation or other differentiation events that accompany AR development. Little is known about the distribution of pectins and AGPs during AR ontogeny, either in the primordium or stem tissues from which AR arise or their correspondence with these events during LR formation. AR form in in vitro cultures of plant parts [6,7,8] and represent a partial regeneration of the plant from which the cells or tissue were taken. AR develop from a variety of stem tissues such as the pericycle, the vascular parenchyma, the phloem and cambium [1, 9, 10]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
