Non-cell-autonomous signaling associated with barley ALOG1 specifies spikelet meristem determinacy.

Inflorescence architecture and crop productivity are often tightly coupled in our major cereal crops. However, the underlying genetic mechanisms controlling cereal inflorescence development remain poorly understood. Here, we identified recessive alleles of barley (Hordeum vulgare L.) HvALOG1 (Arabidopsis thaliana LSH1 and Oryza G1) that produce non-canonical extra spikelets and fused glumes abaxially to the central spikelet from the upper-mid portion until the tip of the inflorescence. Notably, we found that HvALOG1 exhibits a boundary-specific expression pattern that specifically excludes reproductive meristems, implying the involvement of previously proposed localized signaling centers for branch regulation. Importantly, during early spikelet formation, non-cell-autonomous signals associated with HvALOG1 expression may specify spikelet meristem determinacy, while boundary formation of floret organs appears to be coordinated in a cell-autonomous manner. Moreover, barley ALOG family members synergistically modulate inflorescence morphology, with HvALOG1 predominantly governing meristem maintenance and floral organ development. We further propose that spatiotemporal redundancies of expressed HvALOG members specifically in the basal inflorescence may be accountable for proper patterning of spikelet formation in mutant plants. Our research offers new perspectives on regulatory signaling roles of ALOG transcription factors during the development of reproductive meristems in cereal inflorescences.

Anatomical insights into the vascular layout of the barley rachis: implications for transport and spikelet connection.

BACKGROUND AND AIMS: Vascular patterning is intimately related to plant form and function. Here, using barley (Hordeum vulgare) as a model, we studied the vascular anatomy of the spike-type inflorescence. The main aim of the present work was to clarify the relationship between rachis (spike axis) vasculature and spike size, to define vascular dynamics and to discuss the implications for transport capacity and its interaction with the spikelets. METHODS: We used serial transverse internode sections to determine the internode area, vascular area and number of veins along the rachis of several barley lines. KEY RESULTS: Internode area and total vascular area show a clear positive correlation with spike size, whereas the number of veins is only weakly correlated. The lateral periphery of the rachis contains large mature veins of constant size, whereas the central part is occupied by small immature veins. Spikelet-derived veins entering the rachis often merge with the immature rachis veins but never merge with the mature veins. An increase in floret fertility through the conversion of a two-rowed barley into an isogenic six-rowed line, in addition to a decrease in floret fertility owing to enhanced pre-anthesis tip degeneration caused by the mutation tip sterile 2.b (tst2.b), significantly affected vein size but had limited to no effects on the number of veins or internode area. CONCLUSIONS: The rachis vasculature is the result of a two-step process involving an initial layout followed by size adjustment according to floret fertility/spike size. The restriction of large mature vessels to the periphery and that of small immature vessels to the centre of the rachis suggests that long-distance transport and local supply to spikelets are spatially separated processes. The identification of spikelet-derived veins entering the rachis without fusing with its vasculature indicates that a vascular continuity between rachis and spikelets might be non-essential.

The Birth and Death of Floral Organs in Cereal Crops.

Florets of cereal crops are the basic reproductive organs that produce grains for food or feed. The birth of a floret progresses through meristem initiation and floral organ identity specification and maintenance. During these processes, both endogenous and external cues can trigger a premature floral organ death, leading to reproductive failure. Recent advances in different cereal crops have identified both conserved and distinct regulators governing the birth of a floret. However, the molecular underpinnings of floral death are just beginning to be understood. In this review, we first provide a general overview of the current findings in the field of floral development in major cereals and outline different forms of floral deaths, particularly in the Triticeae crops. We then highlight the importance of vascular patterning and photosynthesis in floral development and reproductive success and argue for an expanded knowledge of floral birth-death balance in the context of agroecology. Expected final online publication date for the Annual Review of Plant Biology, Volume 75 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dynamic Phytomeric Growth Contributes to Local Adaptation in Barley.

Vascular plants have segmented body axes with iterative nodes and internodes. Appropriate node initiation and internode elongation are fundamental to plant fitness and crop yield; however, how these events are spatiotemporally coordinated remains elusive. We show that in barley (Hordeum vulgare L.), selections during domestication have extended the apical meristematic phase to promote node initiation, but constrained subsequent internode elongation. In both vegetative and reproductive phases, internode elongation displays a dynamic proximal-distal gradient, and among subpopulations of domesticated barleys worldwide, node initiation and proximal internode elongation are associated with latitudinal and longitudinal gradients, respectively. Genetic and functional analyses suggest that, in addition to their converging roles in node initiation, flowering-time genes have been repurposed to specify the timing and duration of internode elongation. Our study provides an integrated view of barley node initiation and internode elongation and suggests that plant architecture should be recognized as a collection of dynamic phytomeric units in the context of crop adaptive evolution.

Multilayered regulation of developmentally programmed pre-anthesis tip degeneration of the barley inflorescence.

Leaf and floral tissue degeneration is a common feature in plants. In cereal crops such as barley (Hordeum vulgare L.), pre-anthesis tip degeneration (PTD) starts with growth arrest of the inflorescence meristem dome, which is followed basipetally by the degeneration of floral primordia and the central axis. Due to its quantitative nature and environmental sensitivity, inflorescence PTD constitutes a complex, multilayered trait affecting final grain number. This trait appears to be highly predictable and heritable under standardized growth conditions, consistent with a developmentally programmed mechanism. To elucidate the molecular underpinnings of inflorescence PTD, we combined metabolomic, transcriptomic, and genetic approaches to show that barley inflorescence PTD is accompanied by sugar depletion, amino acid degradation, and abscisic acid responses involving transcriptional regulators of senescence, defense, and light signaling. Based on transcriptome analyses, we identified GRASSY TILLERS1 (HvGT1), encoding an HD-ZIP transcription factor, as an important modulator of inflorescence PTD. A gene-edited knockout mutant of HvGT1 delayed PTD and increased differentiated apical spikelets and final spikelet number, suggesting a possible strategy to increase grain number in cereals. We propose a molecular framework that leads to barley PTD, the manipulation of which may increase yield potential in barley and other related cereals.

OsMADS17 simultaneously increases grain number and grain weight in rice.

During the processes of rice domestication and improvement, a trade-off effect between grain number and grain weight was a major obstacle for increasing yield. Here, we identify a critical gene COG1, encoding the transcription factor OsMADS17, with a 65-bp deletion in the 5' untranslated region (5' UTR) presented in cultivated rice increasing grain number and grain weight simultaneously through decreasing mRNA translation efficiency. OsMADS17 controls grain yield by regulating multiple genes and that the interaction with one of them, OsAP2-39, has been characterized. Besides, the expression of OsMADS17 is regulated by OsMADS1 directly. It indicates that OsMADS1-OsMADS17-OsAP2-39 participates in the regulatory network controlling grain yield, and downregulation of OsMADS17 or OsAP2-39 expression can further improve grain yield by simultaneously increasing grain number and grain weight. Our findings provide insights into understanding the molecular basis co-regulating rice yield-related traits, and offer a strategy for breeding higher-yielding rice varieties.

A molecular framework for grain number determination in barley.

Flowering plants with indeterminate inflorescences often produce more floral structures than they require. We found that floral primordia initiations in barley (Hordeum vulgare L.) are molecularly decoupled from their maturation into grains. While initiation is dominated by flowering-time genes, floral growth is specified by light signaling, chloroplast, and vascular developmental programs orchestrated by barley CCT MOTIF FAMILY 4 (HvCMF4), which is expressed in the inflorescence vasculature. Consequently, mutations in HvCMF4 increase primordia death and pollination failure, mainly through reducing rachis greening and limiting plastidial energy supply to developing heterotrophic floral tissues. We propose that HvCMF4 is a sensory factor for light that acts in connection with the vascular-localized circadian clock to coordinate floral initiation and survival. Notably, stacking beneficial alleles for both primordia number and survival provides positive implications on grain production. Our findings provide insights into the molecular underpinnings of grain number determination in cereal crops.

Fluorinated covalent organic frameworks for efficient drug delivery.

In this study, two novel fluorine-functionalized crystalline covalent organic frameworks (COFs), namely DF-TAPB-COF and DF-TATB-COF, were synthesized, and their ordered structure, porosity, suitable pore size, and abundant fluorine groups were expected to serve as effective carriers in drug delivery. The excellent cell viability of DF-TAPB-COF and DF-TATB-COF was verified using MTT assays. Both COFs exhibited very high loading capacities in terms of drug loading performance, in particular the drug loading rate of DF-TAPB-COF for 5-fluorouracil (5-FU) was up to 69%. They also exhibited efficient drug release performance in a simulated body fluid environment. Cell endocytosis experiments demonstrated that DF-TAPB-COF and DF-TATB-COF could be effectively endocytosed by cells. Hence, this study offers new insight into the design and development of COF-based drug carrier systems.

De novo assembly transcriptome analysis reveals the genes associated with body color formation in the freshwater ornamental shrimps Neocaridina denticulate sinensis.

The body color of Neocaridina denticulate sinensis is a compelling phenotypic trait, in which a cascade of carotenoid metabolic processes plays an important role. The study was conducted to compare the transcriptome of cephalothoraxes among three pigmentation phenotypes (red, blue, and chocolate) of N. denticulate sinensis. The purpose of this study was to explore the candidate genes associated with different colors of N. denticulate sinensis. Nine cDNA libraries in three groups were constructed from the cephalothoraxes of shrimps. After assembly, 75022 unigenes were obtained in total with an average length of 1026 bp and N50 length of 1876 bp. There were 45977, 25284, 23605, 21913 unigenes annotated in the Nr, Swissprot, KOG, and KEGG databases, respectively. Differential expression analysis revealed that there were 829, 554, and 3194 differentially expressed genes (DEGs) in RD vs BL, RD vs CH, and BL vs CH, respectively. These DEGs may play roles in the absorption, transport, and metabolism of carotenoids. We also emphasized that electron transfer across the inner mitochondrial membrane (IMM) was a key process in pigment metabolism. In addition, a total of 6328 simple sequence repeats (SSRs) were also detected in N. denticulate sinensis. The results laid a solid foundation for further research on the molecular mechanism of integument pigmentation in the crustacean and contributed to developing more attractive aquatic animals.

Full-length transcriptome sequencing of Heliocidaris crassispina using PacBio single-molecule real-time sequencing.

The lack of high-throughput sequencing data makes the research progress of Heliocidaris crassispina slow. Therefore, we used PacBio single-molecule real-time sequencing to generate the first full-length transcriptome. Here, 31,181 isoforms were obtained, with an average length of 2383.20 and a N50 length of 2732 bp. Meanwhile, 764 alternative splicing (AS) events, 5098 long-noncoding RNAs (LncRNAs), 6978 simple sequence repeats (SSRs), and 950 hypothetical transcript factors (TFs) were identified. Moreover, five key innate immune pattern recognition receptors (PRRs), including toll-like receptor (TLR), NACHT domain and leucine-rich repeat (NLR), scavenger receptor cysteine-rich (SRCR), peptidoglycan recognition proteins (PGRP), and gram-negative binding proteins (GNBP), were searched in the transcriptome. In addition, 37 isoforms enriched in KEGG and GO immune systems were also detected. The study provid abundant data support for the current research on H. crassispina.

Analysis of transcriptome difference between rapid-growing and slow-growing in Penaeus vannamei.

Penaeus vannamei is the principle cultured shrimp species in China. However, with the increase of culture density, the growth difference between individuals is also expanding. Here, we make use of RNA-seq to study the growth mechanisms of P. vannamei. After 120 days, we examined the transcriptomes of rapid-growing individuals (RG) and slow-growing individuals (SG). A total of 2116 and 176 differentially expressed genes (DEGs) were found in SG and RG, respectively. Moreover, the main DEGs are opsin, heat shock protein (HSP), actin, myosin, superoxide dismutase (SOD), cuticle protein, and chitinase. GO analysis further revealed that the DEGs were enriched in biological processes significantly, such as "sensory perception," "sensory perception of light stimulus," "response to stimulus," and "response to stress." Additionally, KEGG enrichment analysis showed that the DEGs were mainly enriched in "pentose and glucuronate interconversions," "amino sugar and nucleotide sugar metabolism," "glycophospholipid biosynthesis," and "glutathione metabolism." Interestingly, the upstream genes in the ecdysone signaling pathway, including molting inhibition hormone (MIH) and crustacean hyperglycemic hormone (CHH), did not differ significantly between RG and SG, which suggests that the cause for the inconsistent growth performance is due to the stress levels rather than the ecdysone signal pathway. In summary, this work provides data that will be useful for future studies on shrimp growth and development.

Variation in the regulatory region of FZP causes increases in secondary inflorescence branching and grain yield in rice domestication.

Inflorescence branching is a key agronomic trait determining rice yield. The primary branch of the ancestral wild rice (Oryza rufipogon Griff.) bears few grains, due to minimal secondary branching. By contrast, Oryza sativa cultivars have been selected to produce large panicles with more secondary branches. Here we showed that the CONTROL OF SECONDARY BRANCH 1 (COS1) gene, which is identical to FRIZZY PANICLE (FZP), plays an important role in the key transition from few secondary branches in wild rice to more secondary branches in domesticated rice cultivars. A 4-bp tandem repeat deletion approximately 2.7 kb upstream of FZP may affect the binding activities of auxin response factors to the FZP promoter, decrease the expression level of FZP and significantly enhance the number of secondary branches and grain yield in cultivated rice. Functional analyses showed that NARROW LEAF 1 (NAL1), a trypsin-like serine and cysteine protease, interacted with FZP and promoted its degradation. Consistently, downregulating FZP expression or upregulating NAL1 expression in the commercial cultivar Zhonghua 17 increased the number of secondary branches per panicle, grain number per panicle and grain yield per plant. Our findings not only provide insights into the molecular mechanism of increasing grain number and yield during rice domestication, but also offer favorable genes for improving the grain yield of rice.

Comparison of clinical efficacy of three surgical methods in the treatment of pterygium.

PURPOSE: To investigate and compare the efficacy of amniotic membrane transplantation, corneal limbus stem cell conjunctival transplantation and pedicle conjunctival flap transposition in the treatment of pterygium. METHODS: A total of 155 patients with pterygium were retrospectively analysed: 53 cases who received amniotic membrane transplantation, 41 who underwent corneal limbus stem cells conjunctival transplantation, and 63 patients who had pedicle conjunctival flap transposition. RESULTS: Patients in the three groups had no significant differences in terms of age, times since surgery, or extent of pterygium extension onto the cornea (F:1.194, 0.639, 0.140 respectively; all P>0.05). A total of 137 out of 155 patients (88.4%) completed 6 months of follow up. The recurrence rates of pterygium for the three surgeries (amniotic membrane transplantation, corneal limbus stem cells conjunctival transplantation and pedicle conjunctival flap transposition) were 14.6%, 13.9% and 7.7%, respectively. No significant difference was identified when comparing the recurrence rate between any two groups (X2: 0.008, 1.211 and 0.890; P: 0.593, 0.218 and 0.276). Five patients presented with postoperative complications, including 3 cases of sub-conjunctival hemorrhage, 1 case of amniotic membrane dissolution, and 1 case of conjunctival cyst, accounting for 3.64% of all participants. CONCLUSION: These three surgical methods are equally effective in preventing the recurrence of pterygium after excision.