Root-associated microbial communities in the soil play fundamental roles in plant nutrition uptake and fitness. However, how plants shape root microbial communities and how the microbes affect the fitness of their hosts remain elusive. Recently, Chinese scientists have made a breakthrough discovery that the nitrogen-use efficiency between indica and japonica rice varieties is associated with different root microbiota in rice. Nitrogen metabolism is greatly enriched in indica-enriched bacteria as compared with japonica-enriched bacteria. Rice NRT1.1B, a nitrogen sensor contributing to nitrogen use divergence between rice subspecies, is associated with the recruitment of these bacterial taxa. Inoculation of the japonica variety with indica-enriched bacteria can improve rice growth in organic nitrogen conditions in the SynCom experimental system. This work highlights the links between root microbiota and nitrogen use in rice and could be exploited to modulate the root microbiota that increase crop productivity and sustainability.

Nucleotide binding, leucine-rich repeat (NLR) immune receptors are a major family of plant resistance (R) proteins, which are also found in animals. NLRs turn on immune signaling by recognizing pathogen-specific effectors in plants. Although the first few plant NLR R genes were cloned more than 25 years ago, the activation mechanism remained elusive. No structure is available for the full-length plant NLRs despite attempts over the last 2 decades. Recently, studies from the Chai, Zhou and Wang labs, published in Science, solved the structure of zygote arrest 1 (ZAR1) before and after effector recognition, which fills a huge gap in NLR biology. This mini review briefly summarized these findings and related progresses, and highlighted further challenges in NLR-mediated immune signaling field.

The most well established auxin signaling pathway is initiated from transport inhibitor response (TIR1)-mediated perception and degradation of Aux/IAAs, eventually leads to depression of auxin response factors (ARFs). A recent study from the Tongda Xu lab showed that high levels of auxin induced the cleavage of the plasma membrane localized transmembrane kinase receptor 1 (TMK1). The cleaved TMK1 C-terminus translocated to the nucleus and phosphorylated the nuclear localized non-canonical IAA32/34, which regulate the auxin signaling response by interacting with ARFs. The TMK1-IAA32/34-ARFs module, acting independently from the TIR1-dependent auxin signaling pathway, nicely interprets how the local auxin accumulation modulates asymmetric growth during apical hook development.

Targeted base editing with CRISPR-Cas systems is a breakthrough in genome editing technologies and is widely used in studies of humans, animals and plants. Recently, Chinese scientists discovered that the cytosine base editor (CBE) including BE3 and HF1-BE3 but not the adenine base editor (ABE) has substantial promise for genome-wide off-targeted editing in rice. This discovery is of great significance to the application and further optimization of targeted base editing.

Abscisic acid (ABA) plays a key role in the growth, development and stress condition of plants. The process of plant response to ABA is completed by signal recognition, transduction, and response cascades. The core ABA signaling pathway consists of receptor RCAR/PYR/PYLs, phosphatase PP2Cs, kinase SnRK2s, and transcription factors and ion channel proteins. Post-translational modifications (PTMs) of proteins such as phosphorylation, ubiquitination, small ubi- quitin-related modifier (SUMOylation) and redox modifications plays an important role in ABA signaling. This review focused on the role of modifications in the core ABA signaling pathway.

The evolution of gene composition of a species is a highly dynamic process, wherein lineage- and species-specific genes originated relatively recently are continuously integrated into the original gene network of older genes. These young genes play important roles in shaping the genome architecture, thereby leading to improved adaptation for organisms. Gene duplication and de novo origination of new genes are two ways to create new genes, causing different gene families with various copy numbers. To what extent and how the evolutionary pattern of genes depends on the timing of gene origination are still largely unexplored in soybean. In this study, we selected 19 representative angiosperms and analyzed the potential relations of the gene content dynamics with the origination of soybean (Glycine max) genes. Using the gene emergence approach, we found that 58.7% of soybean genes could be dated to ~150 million years ago and 21.7% orphan genes had recently originated. As expected, in comparison with young genes, older genes tend to be subjected to stronger purifying selection and were more conserved. In addition, older genes featured higher expression levels and were more likely to undergo alternative splicing. Furthermore, genes with different copy numbers showed a difference in these aspects. These findings may help understand the evolutionary models of genes with different ages.

Chloroplast DNA (cpDNA) can transfer into the plant nuclear genome to form nuclear integrants of plastid DNA (NUPTs). NUPTs may play a role in plant sex chromosome evolution. However, few studies have focused on this research area. In this study, we annotated and analyzed NUPTs in the genome of dioecious Asparagus officinalis and located two cpDNA fragments on chromosomes. The nuclear genome of A. officinalis contains 2 239 NUPT insertions, with total length 565 970 bp, accounting for 0.047% of the genome. The amount of NUPTs differs among chromosomes; the number, density, and the average length of NUPTs on the Y chromosome were all higher than those on the other chromosomes, which indicates more accumulation of NUPTs on sex chromosomes. All regions of inverted repeats (IRs) and small and large single copy regions of cpDNA could transfer into nuclear DNA; however, the IR region showed the highest transfer frequency. Furthermore, FISH analysis of two cpDNA sequences from IR regions showed that AocpIR1 distributed mainly on the centromeres of all chromosomes, whereas AocpIR2 specifically located on sex chromosomes of A. officinalis. The data provide an important foundation for determining the genome structure and sex chromosome evolution of A. officinalis.

In this study, the mature rhizomes of 12 germplasms of Curcuma longa and C. zedoaria from different origins cultivated in Fujian, Quanzhou, were used as experimental materials. The orthogonal design method was used to optimize the extraction of curcumin (CCM), demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC), and the content of 3 curcuminoids and 16 mineral elements in different germplasms were compared. The extraction rate peaked with the following extraction process: 100% methanol as solvent, 1:5 (g·mL^-1) solid-liquid ratio, and ultrasonic extraction for 2 min. The maximum absorption wavelengths for CCM, DMC and BDMC were 424, 418 and 414 nm, respectively. The linear equations for the 3 curcuminoids were Y=0.170 3X+0.024 3 (CCM), Y=0.173 8X+0.041 (DMC), and Y=0.140 6X+0.051 4 (BDMC). The content of CCM, DMC and BDMC in GY03 was 1.23%, 1.22% and 1.50%, respectively, and that of total curcumin was the highest, 3.95%; The content of total curcumin in GY01 was next, up to 3.82%. GY03 and GY01 can be promoted in cultivated land as excellent breeding material. Among the 16 mineral elements detected in 12 turmerics, the contents of Mg, Mn, Al, Fe, and Zn were relatively abundant.

Starch is a main kind of carbohydrates and plays a vital role in energy storage. The granule-bound starch synthase (GBSS) is responsible for the synthesis of amylose. Although GBSS genes have been cloned and identified in many cultivated plants, there are only a few cases of studies on non-cultrivated plants. The present study involved qualitative and quantitative analyses on the sequence characteristics, phylogeny, and expression pattern of GBSS genes in Oryza officinalis. Phylogenetic analysis showed that the GBSS was encoded by two GBSS genes (GBSSI and GBSSII) in all species of Poaceae. In O. officinalis, the two genes shared 62% amino acid identity and displayed different expression patterns in different organs. GBSSII expression was higher in leaves than seeds, whereas GBSSI was mainly expressed in seeds, which suggests divergent spatial expression of the two genes in this wild rice.

Plants from Dipterocarpaceae are vital tropical timber trees in Southeast Asia. They have high potential in forest supervision, forest resource protection and other aspects to evaluate the efficiency of DNA barcodes. We obtained 899 sequences from 244 species for 14 genera combined with sequences from the GenBank. We amplified and sequenced four DNA regions (rbcL, matK, trnL-trnF and ITS2) in samples from the family Dipterocarpaceae. The discrimination ability of DNA barcodes was evaluated by using effective sequence ratios, characteristics of sequences, divergence of intra- and inter-varieties, and identification success rates (Best Match, Best Close Match, BLAST and neighbor-joining methods). The ITS2 fragment showed the highest identification efficiency. High-quality ITS2 sequence can be obtained from the leaves of Dipterocarpaceae plants by using an optimized amplification system. The matK fragment showed obvious genetic variation and 100% amplification and sequencing efficiency, and its identification ability was higher than with other chloroplast markers. Therefore, ITS2 and matK are suitable markers for tropical trees from Dipterocarpaceae.

Pitaya (Hylocereus undulatus) is a tropical fruit developed in recent years. Because its stem is full of polysaccharides, polyphenols and other secondary metabolites, extracting high-quality DNA from the stem is difficult, especially from stems more than 1 year old. At present, there is no good method for DNA extraction. We examined three methods to improve DNA extraction based on the CTAB+Tris-HCl washing method for better and easier DNA extraction. The third method obtained the best-quality DNA without sticky substances from pitaya stem more than 1 year old and was not restricted by sampling data and sampling site. The extracted DNA can be used in enzyme digestion and inter-simple sequence repeat amplification experiments. Our study provides an ideal method for extracting DNA from pitaya stem, which is worth popularizing.

In this research, to establish a tissue culture and rapid propagation system of Ardisia gigantifolia, tender stem segments was selected as explants, and axillary buds were used to study proliferation. Culture medium of MS+1.0 mg·L ^-16-BA+0.2 mg·L ^-1 NAA and MS+0.5 mg·L ^-1 ZT had a significant effect on axillary bud induction and subculture of previous generations; the induction rates were 89.3% and 85.7%, respectively. The best culture medium for the multiplication was MS+0.5 mg·L ^-1 6-BA+0.1 mg·L ^-1 ZT+0.1 mg·L ^-1 NAA, and the propagation coefficient was 4.3. The optimal medium for rooting was 1/2MS+1.5 mg·L ^-1 IAA+1.0 mg·L ^-1NAA; the rooting rate reached 92.3%. The roots developed well and plantlets grew vigorously. Plantlets were transplanted to garden soil:peat soil:perlite=3:1:1 (v/v/v), and 82% rooted plants survived. The study established a fast propagation system for A. gigantifolia that could be applied to factory production.

CRISPR/Cas9 genome editing is used for precisely modifying the genome, enabling nucleotide insertion, deletion, or DNA fragment replacement in targeted gene(s). With more understanding of the CRISPR/Cas9 system, this technology has been widely applied in research, agriculture, medical treatment and other fields. This article briefly introduces the discovery and working principle of the CRISPR/Cas9 genome-editing technology, and summarizes the research progress in optimizing and improving the technology in recent years, including improving the gene editing efficiency, the range expansion of gene editing, base editing and multigene editing, the safety enhancement of genome editing, replacing gene fragments and transcriptional regulation of targeted genes, to provide references for thorough research work in this area.

Sphingolipids are essential components of cell membranes and take part in many critical processes of signal transduction. In plant-fungus interactions, plant sphingolipids mainly induce programmed cell death, whereas fungus sphingolipids induce plant death or plant disease resistance. In this paper, we summarize the structure and metabolic characteristics of plant and fungus sphingolipids as well as advances in the molecular regulation of sphingolipids in plant-fungus interactions. Moreover, the research direction of the role of sphingolipids in plant-fungus symbiosis is also prospected.