Detecting the Different Responses of Roots and Shoots to Gravity in Salix matsudana (Koidz)

The study of the gravity response of roots and shoots is of great significance when exploring the polarity of plants and the development of the forest industry. In our study, normal and inverted cuts of Salix matsudana (Koidz) were cultured. The total RNAs of roots and shoots were extracted. Based on the comparative transcriptome, 412 and 668 genes were differentially expressed. The plasma membrane-, cell wall-, and extracellular region-related genes were up-regulated in the shoots, while the carbon metabolism and the nitrogen metabolism were up-regulated in the roots. Combining the alternative splicing genes, we found a potential gravity response network: in the shoots, LecRLKs were highly sensitive to gravity and further affected the alternative splicing of SNARE, as well as inducing an inhomogeneous distribution of auxin and a negative geotropism curve. In the roots, AP2/ERFs and STRKs were highly sensitive to gravity and regulated the expression level of STPKs and WAKs, finally resulting in a geotropism curve. Moreover, cell division was suppressed in both the roots and the shoots under inverted conditions with different mechanisms. Cell division inhibitors (KRPs) were up-regulated in the roots, while DNA helicase MCMs were down-regulated in the shoots. These results provide an important foundation for further studies of the molecular mechanisms and genetic regulation of plant responses to gravity and the plant polarity of forest trees.

Genome sequencing and phylogenetic analysis of allotetraploid Salix matsudana Koidz

Polyploidy is a common phenomenon among willow species. In this study, genome sequencing was conducted for Salix matsudana Koidz (also named Chinese willow), an important greening and arbor tree species, and the genome of this species was compared with those of four other tree species in Salicaceae. The total genome sequence of S. matsudana was 655.72 Mb in size, with repeated sequences accounting for 45.97% of the total length. In total, 531.43 Mb of the genome sequence could be mapped onto 38 chromosomes using the published genetic map as a reference. The genome of S. matsudana could be divided into two groups, the A and B genomes, through homology analysis with the genome of Populus trichocarpa, and the A and B genomes contained 23,985 and 25,107 genes, respectively. 4DTv combined transposon analysis predicted that allotetraploidy in S. matsudana appeared ~4 million years ago. The results from this study will help reveal the evolutionary history of S. matsudana and lay a genetic basis for its breeding.

Adventitious shoot regeneration from leaf and stem explants of Salix matsudana Koidz

Currently, the leaf and stem as explants for rapid propagation in vitro remained unknown in Salix matsudana. Multiple shoots were regenerated from leaf and stem (stem apex and stem with axil). The optimum medium for callus regeneration and shoots induction from leaf was on WPM medium containing 6.0 mg/l zeatin (Z) and 0.75 mg/l NAA. The optimum medium of shoot induction from stem apex was on MS medium supplemented with 8.0 mg/l Z and 1.0 mg/l NAA, and from stem with axil was on MS with 8.0 mg/l Z and 0.5 mg/l NAA. Rooting of regenerated shoots was obtained on the same medium supplemented with 1.0 mg/l activated charcoal.

ПРОИЗВОДСТВО ПОСАДОЧНОГО МАТЕРИАЛА SALIX MATSUDANA KOIDZ. ДЛЯ ПЛАНТАЦИОННОГО ВЫРАЩИВАНИЯ В УСЛОВИЯХ СЕВЕРО-ВОСТОЧНОЙ ЧАСТИ ЛЕСОСТЕПИ УКРАИНЫ

На основі проведеного дослідження висвітлено окремі елементи агротехніки вирощування контейнерного садивного матеріалу рослин Salix matsudana в умовах закритого та відкритого грунту Сумського НАУ, а також пропонується використовувати саджанці із закритою

ПРОИЗВОДСТВО ПОСАДОЧНОГО МАТЕРИАЛА SALIX MATSUDANA KOIDZ. ДЛЯ ПЛАНТАЦИОННОГО ВЫРАЩИВАНИЯ В УСЛОВИЯХ СЕВЕРО-ВОСТОЧНОЙ ЧАСТИ ЛЕСОСТЕПИ УКРАИНЫ

На основі проведеного дослідження висвітлено окремі елементи агротехніки вирощування контейнерного садивного матеріалу рослин Salix matsudana в умовах закритого та відкритого грунту Сумського НАУ, а також пропонується використовувати саджанці із закритою