Abstract
Despite the large amounts of data available on lateral root formation, little is known about their initiation from secondary structures. In the present work, we applied a bending treatment to Populus nigra (L.) woody taproots to induce the formation of new lateral roots. The development of lateral roots was monitored by stereomicroscopic examination of cross-sections. Tissues were sampled from the bending zone in the proximity of the vascular cambium before (time 0) and after the application of bending at three different time points (24, 48, and 72 h) and analyzed for the expression of P. nigra WOX homologs. The initiation of new lateral roots was observed to originate from the vascular cambium zone and was followed by primordium formation and root emergence. PnWOX4a, PnWOX4b, PnWOX5a, PnWOX5b, PnWOX11/12a, and PnWOX11/12b were shown to be expressed during the formation of new lateral roots at different developmental stages. The mechanical stress simulated by bending treatment was shown to activate the molecular mechanism leading to the expression of WOX genes, which are hypothesized to control SLR formation in the cambium zone of poplar taproot.
Highlights
Despite the large amounts of data available on lateral root formation, little is known about their initiation from secondary structures
Many studies have demonstrated that WUSCHEL-RELATED HOMEOBOX (WOX) transcription factors are involved in controlling the early stages of embryogenesis, the maintenance of meristem activity, and the formation of lateral organs, such as lateral roots, leaves, and floral primordia[1,2]
The analysis showed that the system used for applying bending treatment homogeneously triggered the development of lateral root formation for each of the timepoints considered and across all 15 samples analyzed
Summary
Despite the large amounts of data available on lateral root formation, little is known about their initiation from secondary structures. The mechanical stress simulated by bending treatment was shown to activate the molecular mechanism leading to the expression of WOX genes, which are hypothesized to control SLR formation in the cambium zone of poplar taproot. The two-fold aim of the present study was to investigate, at both the anatomical and molecular level, (i) the tissue originating SLRs in taproot characterized by secondary structure and (ii) if WOX genes could play a role during SLR formation and development in Poplar. We firstly induced SLR formation in Populus nigra (L.) taproot by the application of mechanical stress, and investigated the anatomical traits of crosssections together with the expression of different WOX genes (PnWOXs), through RT-PCR, at four different developmental stages
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have