Overexpression of the ThTPS gene enhanced salt and osmotic stress tolerance in Tamarix hispida

Trehalose is a non-reducing disaccharide with high stability and strong water absorption properties that can improve the resistance of organisms to various abiotic stresses.Trehalose-6-phosphate synthase(TPS)plays important roles in trehalose metabolism and signaling.In this study,the full-length cDNA of ThTPS was cloned from Tamarix hispida Willd.A phylogenetic tree including ThTPS and 11 AtTPS genes from Arabidopsis indicated that the ThTPS protein had a close evolutionary relationship with AtTPS7.However,the function of At TPS7 has not been determined.To analyze the abiotic stress tolerance function of ThTPS,the expression of ThTPS in T.hispida under salt and drought stress and JA,ABA and GA3 hormone stimulation was monitored by qRT-PCR.The results show that ThTPS expression was clearly induced by all five of these treatments at one or more times,and salt stress caused particularly strong induction of Th TPS in the roots of T.hispida.The ThTPS gene was transiently overexpressed in T.hispida.Both physiological indexes and staining results showed that ThTPS gene overexpression increased salt and osmotic stress tolerance in T.hispida.Overall,the Th TPS gene can respond to abiotic stresses such as salt and drought,and its overexpression can significantly improve salt and osmotic tolerance.These findings establish a foundation to better understand the responses of TPS genes to abiotic stress in plants.

Isolation and characterization of the trehalose-6-phosphate synthase gene from Locusta migratoria manilensis

Trehalose plays an important role in protecting organisms from various stresses. Trehalose-6-phosphate synthase （TPS） is the key enzyme in trehalose synthesis, but in insects only a few TPS genes have been identified and their function has not been well characterized. To better understand the function of TPS in insects, a complete TPS complementary DNA （eDNA） clone was obtained from the fat body of the locust Locusta migratoria manilensis （GenBank accession number： EU131894）. The full-length cDNA is 2 806 bp, including an open reading frame of 2 442 bp, which encodes an 813 amino acids protein with a calculated molecular weight of 91 976 Daltons and an isoelectric point of 6.14. The deduced amino acid sequence is highly similar to other published insect TPS and its C-terminal also has a region homologous to trehalose phosphate phsophatase （TPP）. Semi-quantitative analysis indicated that the TPS transcript was expressed not only in fat body, but also in gut, hemolymph and leg muscle. These data may facilitate studies of TPS function in insects and improve our understanding of trehalose metabolism.

RNA interference of a trehalose-6-phosphate synthase gene reveals its roles in the biosynthesis of chitin and lipids in Heortia vitessoides(Lepidoptera:Crambidae)

Trehalose 6-phosphate synthase(TPS),an enzyme that hydrolyzes two glucose molecules to yield trchalose,plays a pivotal role in various physiological processes.In this study,we cloned the trehalose-6-phosphate synthase gene(HvTPS)and investigated its expression patterns in various tssues and d:velopmental stages in Heortia vitessoides Moore(Lepidoptera:Crambidac).HvTPS was highly expressed in the fat body and after pupation or before molting.We knocked down TPS in H.vitessoides by RNA interference and found that 3.0μg of dsHvTPS resulted in optimal interference at 24 h and 36 h post-injection and caused a sharp decline in the survival rate during the 5th instar larval-pupal stage and obviously abnormal or lethal phenotypes.Additionally.compared to the controls,TPS activity and trehalose contents were significantly lower and the glucose content was significantly higher 24 h or 36 h after injection with 3.0μg of dsHIvTPS.Furthermore,the silencing of HvTPS suppressed the cxpression of six key genecs in the chitin biosynthesis pathway and one key gene related to lipid catabolism.The expression levels of two genes associated with lipid biosynthesis were upregulated.These results strongly suggest that HvTPS is essential for the normal growth and development of H.vitessoides and provide a reference for further studies of the utility of key genes involved in chitin and lipid biosynthesis for controlling insect development.

Genomes of Meniocus linifolius and Tetracme quadricornis reveal the ancestral karyotype and genomic features of core Brassicaceae

Brassicaceae represents an important plant family from both a scientific and economic perspective.However,genomic features related to the early diversification of this family have not been fully characterized,especially upon the uplift of the Tibetan Plateau,which was followed by increasing aridity in the Asian interior,intensifying monsoons in Eastern Asia,and significantly fluctuating daily temperatures.Here,we reveal the genomic architecture that accompanied early Brassicaceae diversification by analyzing two high-quality chromosome-level genomes for Meniocus linifolius(Arabodae;clade D)and Tetracme quadricornis(Hesperodae;clade E),together with genomes representing all major Brassicaceae clades and the basal Aethionemeae.We reconstructed an ancestral core Brassicaceae karyotype(CBK)containing 9 pseudochromosomes with 65 conserved syntenic genomic blocks and identified 9702 conserved genes in Brassicaceae.We detected pervasive conflicting phylogenomic signals accompanied by widespread ancient hybridization events,which correlate well with the early divergence of core Brassicaceae.We identified a successive Brassicaceae-specific expansion of the class I TREHALOSE-6-PHOSPHATE SYNTHASE 1(TPS1)gene family,which encodes enzymes with essential regulatory roles in flowering time and embryo development.The TPS1s were mainly randomly amplified,followed by expression divergence.Our results provide fresh insights into historical genomic features coupled with Brassicaceae evolution and offer a potential model for broad-scale studies of adaptive radiation under an ever-changing environment.