RESUMEN
Pratylenchus vulnus (walnut root lesion nematode) is one of the most damaging root lesion nematode species worldwide. In this study, 17 populations of P. vulnus obtained from wheat and barley cultivated fields in 2016 to 2017 in Turkey (Karaman and Konya provinces) were identified using real-time PCR and melting curve analysis. Samples provided a single peak at 87.3ËC with real-time PCR. D2 to D3 expansion segments of the 28S rRNA of one population from Cihanbeyli district in Konya province was sequenced and recorded in GenBank (Accession number: MT320536.1). Alignments of the population was identical 98.66% to the populations of P. vulnus available in GenBank (Accs. nos: LT985479.1 and LT965052.1) and 98.65% (Accs. nos: KY424305.1 and KY424304.1).
RESUMEN
The epidermis is hypothesized to play a signalling role during plant development. One class of mutants showing defects in signal transduction and radial patterning are those in sterol biosynthesis. The expectation is that living cells require sterols, but it is not clear that all cell types express sterol biosynthesis genes. The HYDRA1 (HYD1) gene of Arabidopsis encodes sterol Δ8-Δ7 isomerase, and although hyd1 seedlings are defective in radial patterning across several tissues, we show that the HYD1 gene is expressed most strongly in the root epidermis. Transgenic activation of HYD1 transcription in the epidermis of hyd1 null mutants reveals a major role in root patterning and growth. HYD1 expression in the vascular tissues and root meristem, though not endodermis or pericycle, also leads to some phenotypic rescue. Phenotypic rescue is associated with rescued patterning of the PIN1 and PIN2 auxin efflux carriers. The importance of the epidermis in controlling root growth and development is proposed to be, in part, due to its role as a site for sterol biosynthesis, and auxin is a candidate for the non-cell-autonomous signal.
