Genomic analysis reveals phylogeny of Zygophyllales and mechanism for water retention of a succulent xerophyte.

Revealing the genetic basis for stress-resistant traits in extremophile plants will yield important information for crop improvement. Zygophyllum xanthoxylum, an extant species of the ancient Mediterranean, is a succulent xerophyte that can maintain a favorable water status under desert habitats; however, the genetic basis of this adaptive trait is poorly understood. Furthermore, the phylogenetic position of Zygophyllales, to which Z. xanthoxylum belongs, remains controversial. In this study, we sequenced and assembled the chromosome-level genome of Z. xanthoxylum. Phylogenetic analysis showed that Zygophyllales and Myrtales form a separated taxon as a sister to the clade comprising fabids and malvids, clarifying the phylogenetic position of Zygophyllales at whole-genome scale. Analysis of genomic and transcriptomic data revealed multiple critical mechanisms underlying the efficient osmotic adjustment using Na+ and K+ as "cheap" osmolytes that Z. xanthoxylum has evolved through the expansion and synchronized expression of genes encoding key transporters/channels and their regulators involved in Na+/K+ uptake, transport, and compartmentation. It is worth noting that ZxCNGC1;1 (cyclic nucleotide-gated channels) and ZxCNGC1;2 constituted a previously undiscovered energy-saving pathway for Na+ uptake. Meanwhile, the core genes involved in biosynthesis of cuticular wax also featured an expansion and upregulated expression, contributing to the water retention capacity of Z. xanthoxylum under desert environments. Overall, these findings boost the understanding of evolutionary relationships of eudicots, illustrate the unique water retention mechanism in the succulent xerophyte that is distinct from glycophyte, and thus provide valuable genetic resources for the improvement of stress tolerance in crops and insights into the remediation of sodic lands.

Clinical Randomized Controlled Study of Acupuncture Treatment on Children with Autism Spectrum Disorder (ASD): A Systematic Review and Meta-Analysis.

This study aimed to summarize the effectiveness and safety of acupuncture in the treatment of autism spectrum disorder (ASD) through literature analysis and evaluation. All studies were retrieved from various databases as follows: English databases, such as PubMed, Cochrane Library, Ovid, and Web of Science, and Chinese databases, such as China National Knowledge Infrastructure (CNKI), WanFang Data (WF), and Technology Periodical Database (VIP). The Cochrane Collaboration's Bias Risk Assessment Scale was used to assess the studies' risk of bias. The effects of acupuncture treatment for ASD were determined using the following indicators: childhood autism rating scale (CARS), autism behavior check list (ABC), Reynell developmental language scale (RDLS), and functional independence measure of children (WeeFIM). The risk map of bias of these studies' quality and the meta-analysis results of the indicators was prepared with RevMan 5.2 software. Finally, 16 studies were included, five of which were in English and 11 were in Chinese. The 16 studies included 1332 patients. The CARS results for subgroup analysis were as follows: acupuncture subgroup (MD = -2.65, 95% CI (-3.22, -2.07)) and acupuncture plus massage subgroup (MD = -10.35, 95% CI (-11.34, -9.36)). The ABC results were as follows: (MD = -6.70, 95% CI (-9.10, -4.29)). The analysis results of sensory, relating, language, body and object use, and social/self-help in the subitems of ABC were as follows: sensory (MD = -2.67, 95% CI (-2.90, -2.44)), relating (MD = -3.28, 95% CI (-3.55, -3.02)), language (MD = -2.45, 95% CI (-2.73, -2.16)), body and object use (MD = -1.19, 95% CI (-1.38, -1.00)), and social/self-help (MD = -2.09, 95% CI (-2.30, -1.89)). For the analysis results of comprehension and expression ages in the subitems of RDLS, the comprehension age results were as follows: (MD = 0.08, 95% CI (-0.06, 0.22), P = 0.27). Those of expression age were as follows: (MD = 0.15, 95% CI (0.04, 0.26), P=0.009). The WeeFIM results were as follows: (MD = 3.70, 95% CI (2.38, 5.02)). This study suggested that acupuncture could effectively treat ASD. However, acupuncture methods and prescriptions at this stage remain heterogeneous, and acupuncture treatment operations require standardization. Studies using rigorous and standard research designs are needed to draw stronger conclusions about the advantages of using acupuncture to treat children and adolescents with ASD.

ZxNHX1 indirectly participates in controlling K+ homeostasis in the xerophyte Zygophyllum xanthoxylum.

The succulent xerophyte Zygophyllum xanthoxylum (Bunge) Engl. can absorb Na+ from the soil as an osmoticum in order to resist osmotic stress. The tonoplast Na+/H+ antiporter ZxNHX1 is essential for maintaining the salt-accumulation characteristics of Z. xanthoxylum by compartmentalizing Na+ into vacuoles. Previous results revealed that the silencing of ZxNHX1 greatly decreased Na+ accumulation in Z. xanthoxylum under 50 mM NaCl due to the weakened compartmentalisation; in addition, K+ concentration also significantly reduced in ZxNHX1-RNAi lines. Yet, whether the reduction of K+ concentration was directly triggered by the silencing of ZxNHX1 remains unclear. In this study, the growth parameters and expression levels of ZxSOS1, ZxHKT1;1, ZxAKT1 and ZxSKOR were measured in wild-type and ZxNHX1-RNAi lines under control or -0.5 MPa osmotic stress. The results showed that the silencing of ZxNHX1 inhibited the plant growth, decreased Na+ concentration in leaves, reduced the transcript abundance of ZxSOS1 and dramatically increased that of ZxHKT1;1 in roots of Z. xanthoxylum under osmotic stress; whereas tissue K+ concentrations and the expression level of ZxSKOR displayed no significant variations, and the expression of ZxAKT1 were significantly reduced in ZxNHX1-RNAi lines under osmotic stress, compared with the wild type. These results suggest that in Z. xanthoxylum, ZxNHX1 can maintain the normal growth by compartmentalizing Na+ into vacuoles, and regulate the spatial distribution of Na+ indirectly by affecting the expressions of ZxSOS1 and ZxHKT1;1. Moreover, the silencing of ZxNHX1 is not the main reason that led to the reduction of K+ concentration in ZxNHX1-RNAi lines under 50 mM NaCl, and ZxNHX1 might be indirectly involved in regulating K+ homeostasis.

Cloning and functional characterization of epidermis-specific promoter MtML1 from Medicago truncatula.

Epidermis-specific promoters are necessary for ectopic expression of specific functional genes such as the cuticle-related genes. Previous studies indicated that both ECERIFERUM 6 (AtCER6) and MERISTEM L1 LAYER (ATML1) promoters from Arabidopsis thaliana can drive gene expression specifically in the epidermis of shoot apical meristems (SAMs) and leaves. However, the epidermis-specific promoters from legume plants have not been reported. Here, we cloned a 5' flanking sequence from the upstream -2150 bp to the translational start ATG codon of MtML1 gene of legume model plant Medicago truncatula. PlantCARE analysis indicated that this sequence matches the characteristics of a promoter, having TATA box and CAAT box, as well as contains some conserved elements of epidermis-specific promoters like AtCER6 and ATML1 promoters. The ß-glucuronidase (GUS) histochemical analysis showed that MtML1 promoter can drive GUS gene expression in transiently transformed Nicotiana tabacum leaves under non-inducing condition. Furthermore, it can also control GUS expression in leaves and siliques rather than roots of the stably transformed Arabidopsis. More importantly, the leaf cross-section observations indicated that MtML1 exclusively expressed in the epidermis of leaves. These results suggested that MtML1 promoter performed the epidermis-specific in plant shoot. Our study establishes the foundation for driving the cuticle-related gene to express in epidermis, which may be very useful in genetic engineering of legume plants.