Tissue distribution of Lycium barbarum polysaccharides in rat tissue by fluorescein isothiocyanate labeling

To date, in vivo investigations of polysaccharide’s pharmacokinetics are significantly restricted by the difficulty in their detection. This study was conducted to establish the quantitative determination of Lycium barbarum polysaccharides(LBPs) based on fluorescein isothiocyanate(FITC) pre-labeling and to investigate their tissue distribution in rat. We obtained the calibration curves linear over the range of 0.0–25 μg/m L in rat tissue samples with correlation coefficients greater than 0.99. The inter-day and intra-day precisions(RSD, %) were within 15%, and the relative recovery ranged 95.2%–102.4%, with RSD range 1.48%–9.58%, indicating that this experiment was suitable for the determination of LBPs. The fluorescence intensity was measured after 24 h storage at room temperature, 3 times of freeze-cycle and cryopreservation at –20 ℃ for 15 day, these results indicated that the stability of the samples was good. LBP-FITC was mainly absorbed by the small intestine and stomach, and mainly excreted in the urine through the kidney;this distinct difference in the tissue distribution of LBPs could be attributed to the size of these LBPs in relation to the pore sizes of the vascular beds in the kidney and liver. Results showed in this study enable us to comprehensively understand the biological effects of LBPs following its oral ingestion.

Development of a haploid inducer by editing HvMTL in barley

The doubled-haploid technique mediated by parthenogenesis and androgenesis in plants can directly generate homozygous diploid lines after chromosome doubling with colchicine in one or two generations,and this method undoubtedly shortens the breeding process and improves breeding efficiency in crops.Previously,haploid plants were mainly induced by anther culture or microspore culture via androgenesis(Ohnoutkova et al.,2019).In wheat(Triticum aestivum),haploids can also be induced by maize(Zea mays)pollen and chromosome elimination via parthenogenesis(Liu et al.,2020b).However,the aforementioned induction methods are genotype-dependent,require complex manipulations,and are both time-consuming and inefficient.Therefore,it is necessary to develop new techniques or germplasm for simple and efficient haploid induction.

A fast technique for visual screening of wheat haploids generated from TaMTL-edited mutants carrying anthocyanin markers

Dear Editor,Breeding a new wheat variety using traditional methods typically takes at least 8 to 10 years,and the breeding period can be dramatically shortened via a doubled haploid strategy,which can yield homozygotes within one or two generations.In the past several decades,wheat haploids have been widely induced through anther or microspore culture and chromosome elimination via interspecific hybridization between wheat and maize.The first technique exhibits strong genotype dependency and a severe albino phenomenon,whereas the latter shows low induction efficiency(Sangam et al.,2015).In addition,haploid induction procedures using the aforementioned methods are complicated to perform and require specialized equipment and environmentally controlled conditions.Thus,the application of these technologies in wheat breeding has been limited(Sangam et al.,2015).

Establishment of a transformation system in close relatives of wheat under the assistance of TaWOX5

Species closely related to wheat are important genetic resources for agricultural production,functional genomics studies and wheat improvement.In this study,a wheat gene related to regeneration,TaWOX5,was applied to establish the Agrobacterium-mediated transformation systems of Triticum monococcum,hexaploid triticale,and rye(Secale cereale L.)using their immature embryos.Transgenic plants were efficiently generated.During the transformation process,the Agrobacterium infection efficiency was assessed by histochemical staining forβ-glucuronidase(GUS).Finally,the transgenic nature of regenerated plants was verified by polymerase chain reaction(PCR)-based genotyping for the presence of the GUS and bialaphos resistance(bar)genes,histochemical staining for GUS protein,and the QuickStix strip assay for bar protein.The transformation efficiency of T.monococcum genotype PI428182 was 94.4%;the efficiencies of four hexaploid triticale genotypes Lin456,ZS3297,ZS1257,and ZS3224 were 52.1,41.2,19.4,and 16.0%,respectively;and the transformation efficiency of rye cultivar Lanzhou Heimai was 7.8%.Fluorescence in situ hybridization(FISH)and genomic in situ hybridization(GISH)analyses indicated that the GUS transgenes were integrated into the distal or near centromere(proximal)regions of the chromosomes in transgenic T.monococcum and hexaploid triticale plants.In the transgenic hexaploid triticale plants,the foreign DNA fragment was randomly integrated into the AABB and RR genomes.Furthermore,the transgene was almost stably inherited in the next generation by Mendel’s law.The findings in this study will promote the genetic improvement of the three plant species for grain or forage production and the improvement of cereal species including wheat for functional genomics studies.

CRISPR/Cas9 editing of wheat TaQ genes alters spike morphogenesis and grain threshability

The Ta Q alleles as one of the AP2-like transcription factors in common wheat(Triticum aestivum) play an important role in the evolution of spike characteristics from wild and domesticated emmer to modern wheat cultivars. Its loss-of-function mutant not only changed threshability and spike architecture but also affected plant height, flowering time, and floret structure. However, the comprehensive functions of Ta AQ and Ta Dq genes in wheat have not been fully elucidated yet. Here, CRISPR/Sp Cas9 was used to edit wheat Ta AQ and Ta Dq. We obtained homozygous plants in the T1 generation with loss of function of only Ta AQ or Ta Dq and simultaneous loss of function of Ta AQ and Ta Dq to analyze the effect of these genes on wheat spikes and floret shapes. The results demonstrated that the Ta AQ-edited plants and the Ta AQ and Ta Dq simultaneously-edited plants were nearly similar in spike architecture, whereas the Ta Dq-edited plants were different from the wild-type ones only in plant height. Moreover, the Ta AQ-edited plants or the Ta AQ and Ta Dq simultaneously-edited plants were more brittle than the wild-type and the Ta Dqedited plants. Based on the expression profiling, we postulated that the VRN1, FUL2, SEP2, SEP5, and SEP6 genes might affect the number of spikelets and florets per spike in wheat by regulating the expression of Ta Q. Combining the results of this report and previous reports, we conceived a regulatory network of wheat traits, including plant height, spike shape, and floral organs, which were influenced by AP2-like family genes. The results achieved in this study will help us to understand the regulating mechanisms of Ta AQ and Ta Dq alleles on wheat floral organs and inflorescence development.