Influence of low-vacuum helium cold plasma pre-treatment on the rooting and root growth of zoysiagrass(Zoysia Willd.) stolon cuttings

The influence of low-vacuum helium cold plasma treatment on the rooting percentage,root growth and physiochemical properties of zoysiagrass stolon cuttings was studied.Zoysiagrass stolon cuttings were pre-treated with 0,100,200,300 and 400 W of cold plasma for 15 s.The cold plasma positively stimulated rooting and improved the root growth of the zoysiagrass stolon cuttings,and the 300 W treatment produced the best effect.The rooting percentage and root growth parameters,including the root length,total root surface area,total root volume,average root diameter,and root dry weight,significantly improved in response to the cold plasma treatment.In addition,the water uptake and relative conductivity of the stolon cuttings increased significantly in response to the cold plasma treatment.The results revealed that cold plasma-stimulated rooting and root growth appear to be a consequence of the improvement in permeability and water absorbing capacity of zoysiagrass stolon cuttings.The results of the present study will provide inspiration and support for the application of cold plasma in the vegetative propagation of plants.

Phosphorylation regulation of nitrogen,phosphorus,and potassium uptake systems in plants

The uptake of ammonium,nitrate,phosphorus,and potassium ions by roots is mediated by specific ion transporter or channel proteins,and protein phosphorylation regulation events occurring on these proteins and their regulators determine their ultimate activity.Elucidating the mechanism by which protein phosphorylation modification regulates nutrient uptake will advance plant breeding for high nutrientuse efficiency.In this review,it is concluded that the root nutrient absorption system is composed of several,but not all,members of a specific ion transporter or channel family.Under nutrient-starvation conditions,protein phosphorylation-based regulation of these proteins and associated transcription factors increases ion transporter-or channel-mediated nutrient uptake capacity via direct function activity enhancement,allowing more protein trafficking to the plasma membrane,by strengthening the interaction of transporters and channels with partner proteins,by increasing their protein stability,and by transcriptional activation.Under excessive nutrient conditions,protein phosphorylation-based regulation suppresses nutrient uptake by reversing these processes.Strengthening phosphorylation regulation items that increase nutrient absorption and weakening phosphorylation modification items that are not conducive to nutrient absorption show potential as strategies for increasing nutrient use efficiency.

A high-quality chromosome-scale assembly of the centipedegrass[Eremochloa ophiuroides(Munro)Hack.]genome provides in sights into chromosomal structural evolution and prostrate growth habit

Centipedegrass[Eremochloa ophiuroides(Munro)Hack.],a member of the Panicoideae subfamily,is one of the most important warm-season turfgrasses originating from China.This grass has an extremely developed prostrate growth habit and has been widely used in transitional and warm climatic regions.To better understand the genetic basis of important biological characteristics,such as prostrate growth and seed yield,in warm-season turfgrasses,we present a high-quality reference genome for centipedegrass and use PacBio,BioNano,and Hi-C technologies to anchor the 867.43 Mb genome assembly into nine pseudochromosomes,with a scaffold N50 of 86.05 Mb and 36,572 annotated genes.Centipedegrass was most closely related to sorghum and diverged from their common ancestor~16.8 Mya.We detected a novel chromosome reshuf fling event in centipedegrass,namely,the nest chromosome fusion event in which fusion of chromosomes 8 and 10 of sorghum into chromosome 3 of centipedegrass likely occurred after the divergence of centipedegrass from sorghum.The typical prostrate growth trait in centipedegrass may be linked to the expansion of candidate PROSTRATE GROWTH 1(PROG1)genes on chromosome 2.Two orthologous genes of OsPROGl,EoPROGl,and EoPROG2,were con firmed to increase the stem number and decrease the stem angle in Arabidopsis.Collectively,our assembled reference genome of centipedegrass offers new knowledge and resources to dissect the genome evolution of Panicoideae and accelerate genome-assisted breeding and improvement of plant architecture in turf plants.

Genetic diversity in centipedegrass[Eremochloa ophiuroides(Munro)Hack.]

Genetic diversity is the heritable variation within and among populations,and in the context of this paper describes the heritable variation among the germplasm resources of centipedegrass.Centipedegrass is an important warmseason perennial C4 grass belonging to the Poaceae family in the subfamily Panicoideae and genus Eremochloa.It is the only species cultivated for turf among the eight species in Eremochloa.The center of origin for this species is southern to central China.Although centipedegrass is an excellent lawn grass and is most widely used in the southeastern United States,China has the largest reserve of centipedegrass germplasm in the world.Presently,the gene bank in China holds~200 centipedegrass accessions collected from geographical regions that are diverse in terms of climate and elevation.This collection appears to have broad variability with regard to morphological and physiological characteristics.To efficiently develop new centipedegrass varieties and improve cultivated species by fully utilizing this variability,multiple approaches have been implemented in recent years to detect the extent of variation and to unravel the patterns of genetic diversity among centipedegrass collections.In this review,we briefly summarize research progress in investigating the diversity of centipedegrass using morphological,physiological,cytological,and molecular biological approaches,and present the current status of genomic studies in centipedegrass.Perspectives on future research on genetics and genomics and modern breeding of centipedegrass are also discussed.

State laws governing school physical education in relation to attendance and physical activity among students in the USA: A systematic review and meta-analysis

Background:This study systematically synthesized and quantified the relationship linking state laws governing school physical education(PE)to PE attendance and physical activity(PA)in class and throughout the day and week among students in the USA.Methods:A keyword search was performed in PubMed,Web of Science,Cumulative Index to Nursing and Allied Health Literature(CINAHL),Academic Search Complete,and EconLit.Meta-analyses were performed to estimate the effects of state PE laws.Results:A total of 17 studies were included in the review,and five contributed to the meta-analyses.A total of 8 studies used nationally representative school-or student-level data,three focused on multiple states,and the remaining six examined the PE laws of a single state.The presence and strength of state PE laws were positively associated with PE attendance and the frequency and duration of PA during PE classes and throughout the school day.Compared to those residing in states with weak or no PE laws,students in states with strong PE laws had an additional 0.2 days(95%confidence interval(95%CI):0.10.4)of PE attendance per week and spent an additional 33.9 min(95%CI:22.745.0)participating PE classes per week.State PE laws affected girls’PA more than boys’.Different aspects of state PE laws tended to affect students’PE attendance differently.Disparities in the implementation of state PE laws existed across schools.Conclusion:Future studies should adopt objective measures on PE and PA participation and examine the roles schools and districts play in mediating the effect of state PE laws on students’PE attendance and PA.

Trajectory tracking control of quantum systems

For quantum state trajectory tracking of density matrix in Liouville equation of quantum systems,with the help of concept in quantum system control,one can apply unitary transformation both to controlled system and free-evolutionary target system such as to change the time-variant and non-stationary target system into a stationary state.Therefore,the quantum state trajectory tracking problem becomes a steering one.State steering control law of the system transformed is designed by means of the Lyapunov stability theorem.Finally,numerical simulation experiments are given for a five-level energy quantum system.The comparison analysis of original system's trajectory tracking with other method illustrates the advantage in control time of the method proposed.