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Low phosphate (Pi) availability decreases photosynthesis, with phosphate limitation of photosynthesis occurring particularly during grain filling of cereal crops; however, effective genetic solutions remain to be established. We previously discovered that rice phosphate transporter OsPHO1;2 controls seed (sink) development through Pi reallocation during grain filling. Here, we find that OsPHO1;2 regulates Pi homeostasis and thus photosynthesis in leaves (source). Loss-of-function of OsPHO1;2 decreased Pi levels in leaves, leading to decreased photosynthetic electron transport activity, CO 2 assimilation rate, and early occurrence of phosphate-limited photosynthesis. Interestingly, ectopic expression of OsPHO1;2 greatly increased Pi availability, and thereby, increased photosynthetic rate in leaves during grain filling, contributing to increased yield. This was supported by the effect of foliar Pi application. Moreover, analysis of core rice germplasm resources revealed that higher OsPHO1;2 expression was associated with enhanced photosynthesis and yield potential compared to those with lower expression. These findings reveal that phosphate-limitation of photosynthesis can be relieved via a genetic approach, and the OsPHO1;2 gene can be employed to reinforce crop breeding strategies for achieving higher photosynthetic efficiency., Competing Interests: Competing interests statement:The authors declare no competing interest.

Objective: This study aimed to assess the impact of a lung-protective ventilation strategy utilizing transpulmonary driving pressure titrated positive end-expiratory pressure (PEEP) on the prognosis [mechanical ventilation duration, hospital stay, 28-day mortality rate and incidence of ventilator-associated pneumonia (VAP), survival outcome] of patients with Acute Respiratory Distress Syndrome (ARDS)., Methods: A total of 105 ARDS patients were randomly assigned to either the control group (n = 51) or the study group (n = 53). The control group received PEEP titration based on tidal volume [A tidal volume of 6 mL/kg, flow rate of 30-60 L/min, frequency of 16-20 breaths/min, constant flow rate, inspiratory-to-expiratory ratio of 1:1 to 1:1.5, and a plateau pressure ≤ 30-35 cmH 2 O. PEEP was adjusted to maintain oxygen saturation (SaO 2 ) at or above 90%, taking into account blood pressure], while the study group received PEEP titration based on transpulmonary driving pressure (Esophageal pressure was measured as a surrogate for pleural pressure using an esophageal pressure measurement catheter connected to the ventilator. Tidal volume and PEEP were adjusted based on the observed end-inspiratory and end-expiratory transpulmonary pressures, aiming to maintain a transpulmonary driving pressure below 15 cmH 2 O during mechanical ventilation. Adjustments were made 2-4 times per day). Statistical analysis and comparison were conducted on lung function indicators [oxygenation index (OI), arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2)] as well as other measures such as heart rate, mean arterial pressure, and central venous pressure in two groups of patients after 48 h of mechanical ventilation. The 28-day mortality rate, duration of mechanical ventilation, length of hospital stay, and ventilator-associated pneumonia (VAP) incidence were compared between the two groups. A 60-day follow-up was performed to record the survival status of the patients., Results: In the control group, the mean age was (55.55 ± 10.51) years, with 33 females and 18 males. The pre-ICU hospital stay was (32.56 ± 9.89) hours. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was (19.08 ± 4.67), and the mean Murray Acute Lung Injury score was (4.31 ± 0.94). In the study group, the mean age was (57.33 ± 12.21) years, with 29 females and 25 males. The pre-ICU hospital stay was (33.42 ± 10.75) hours. The mean APACHE II score was (20.23 ± 5.00), and the mean Murray Acute Lung Injury score was (4.45 ± 0.88). They presented a homogeneous profile (all P > 0.05). Following intervention, significant improvements were observed in PaO 2 and OI compared to pre-intervention values. The study group exhibited significantly higher PaO 2 and OI compared to the control group, with statistically significant differences (all P < 0.05). After intervention, the study group exhibited a significant increase in PaCO2 (43.69 ± 6.71 mmHg) compared to pre-intervention levels (34.19 ± 5.39 mmHg). The study group's PaCO2 was higher than the control group (42.15 ± 7.25 mmHg), but the difference was not statistically significant (P > 0.05). There were no significant differences in hemodynamic indicators between the two groups post-intervention (all P > 0.05). The study group demonstrated significantly shorter mechanical ventilation duration and hospital stay, while 28-day mortality rate and incidence of ventilator-associated pneumonia (VAP) showed no significant differences. Kaplan-Meier survival analysis revealed a significantly better survival outcome in the study group at the 60-day follow-up (HR = 0.565, 95% CI: 0.320-0.999)., Conclusion: Lung-protective mechanical ventilation using transpulmonary driving pressure titrated PEEP effectively improves lung function, reduces mechanical ventilation duration and hospital stay, and enhances survival outcomes in patients with ARDS. However, further study is needed to facilitate the wider adoption of this approach., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Crop phenomics enables the collection of diverse plant traits for a large number of samples along different time scales, representing a greater data collection throughput compared with traditional measurements. Most modern crop phenomics use different sensors to collect reflective, emitted, and fluorescence signals, etc., from plant organs at different spatial and temporal resolutions. Such multi-modal, high-dimensional data not only accelerates basic research on crop physiology, genetics, and whole plant systems modeling, but also supports the optimization of field agronomic practices, internal environments of plant factories, and ultimately crop breeding. Major challenges and opportunities facing the current crop phenomics research community include developing community consensus or standards for data collection, management, sharing, and processing, developing capabilities to measure physiological parameters, and enabling farmers and breeders to effectively use phenomics in the field to directly support agricultural production., Competing Interests: Conflict of interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The dramatic decrease in atmospheric CO 2 concentration during Oligocene was proposed as directly linked to C 4 evolution. However, it remains unclear how the decreased CO 2 concentration directly facilitate C 4 evolution, besides its role as a selection pressure. We conducted a systematic transcriptomics and metabolomics analysis under short-term low CO 2 condition and found that Arabidopsis grown under this condition showed 1) increased expression of most genes encoding C 4 -related enzymes and transporters; 2) increased expression of genes involved in photorespiration and pathways related to carbon skeleton generation for ammonium refixation; 3) increased expression of genes directly involved in ammonium refixation. Furthermore, we found that in vitro treatment of leaves with NH 4 + induced a similar pattern of changes in C 4 related genes and genes involved in ammonium refixation. These data support the view that Arabidopsis grown under short-term low CO 2 conditions rewired its metabolism to supply carbon skeleton for ammonium recycling, during which process the expression of C 4 genes were up-regulated as a result of a hitchhiking process. This study provides new insights into the adaptation of the C 3 model plant Arabidopsis under low CO 2 conditions and suggests that low CO 2 can facilitate the evolution of C 4 photosynthesis beyond the commonly assumed role of being a selection pressure., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Miao, Wang, Haq, Lyu and Zhu.)

Background: The interplay between diabetes mellitus (DM), glycemic traits, and vascular and valvular calcifications is intricate and multifactorial. Exploring potential mediators may illuminate underlying pathways and identify novel therapeutic targets., Methods: We utilized univariable and multivariable Mendelian randomization (MR) analyses to investigate associations and mediation effects. Additionally, the multivariable MR analyses incorporated cardiometabolic risk factors, allowing us to account for potential confounders., Results: Type 2 diabetes mellitus (T2DM) and glycated hemoglobin (HbA1c) were positively associated with both coronary artery calcification (CAC) and calcific aortic valvular stenosis (CAVS). However, fasting glucose (FG) was only linked to CAVS and showed no association with CAC. Additionally, CAVS demonstrated a causal effect on FG. Calcium levels partially mediated the impact of T2DM on both types of calcifications. Specifically, serum calcium was positively associated with both CAC and CAVS. The mediation effects of calcium levels on the impact of T2DM on CAC and CAVS were 6.063% and 3.939%, respectively. The associations between T2DM and HbA1c with calcifications were influenced by body mass index (BMI) and smoking status. However, these associations were generally reduced after adjusting for hypertension., Conclusion: Our findings suggest a genetically supported causal relationship between DM, glycemic traits, and vascular and valvular calcifications, with serum calcium playing a critical mediating role., (© 2024. The Author(s).)

Improving photosynthesis, the fundamental process by which plants convert light energy into chemical energy, is a key area of research with great potential for enhancing sustainable agricultural productivity and addressing global food security challenges. This perspective delves into the latest advancements and approaches aimed at optimizing photosynthetic efficiency. Our discussion encompasses the entire process, beginning with light harvesting and its regulation and progressing through the bottleneck of electron transfer. We then delve into the carbon reactions of photosynthesis, focusing on strategies targeting the enzymes of the Calvin-Benson-Bassham (CBB) cycle. Additionally, we explore methods to increase CO2 concentration near the Rubisco, the enzyme responsible for the first step of CBB cycle, drawing inspiration from various photosynthetic organisms, and conclude this section by examining ways to enhance CO2 delivery into leaves. Moving beyond individual processes, we discuss two approaches to identifying key targets for photosynthesis improvement: systems modeling and the study of natural variation. Finally, we revisit some of the strategies mentioned above to provide a holistic view of the improvements, analyzing their impact on nitrogen use efficiency and on canopy photosynthesis., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

As a complex trait, C4 photosynthesis has multiple independent origins in evolution. Phylogenetic evidence and theoretical analysis suggest that C2 photosynthesis, which is driven by glycine decarboxylation in the bundle sheath cell, may function as a bridge from C3 to C4 photosynthesis. However, the exact molecular mechanism underlying the transition between C2 photosynthesis to C4 photosynthesis remains elusive. Here, we provide evidence suggesting a role of higher α-ketoglutarate (AKG) concentration during this transition. Metabolomic data of 12 Flaveria species, including multiple photosynthetic types, show that AKG concentration initially increased in the C3-C4 intermediate with a further increase in C4 species. Petiole feeding of AKG increases the concentrations of C4-related metabolites in C3-C4 and C4 species but not the activity of C4-related enzymes. Sequence analysis shows that glutamate synthase (Fd-GOGAT), which catalyzes the generation of glutamate using AKG, was under strong positive selection during the evolution of C4 photosynthesis. Simulations with a constraint-based model for C3-C4 intermediate further show that decreasing the activity of Fd-GOGAT facilitated the transition from a C2-dominant to a C4-dominant CO2 concentrating mechanism. All these results provide insight into the mechanistic switch from C3-C4 intermediate to C4 photosynthesis., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

AP2 / ERF transcription factor family plays an important role in plant development and stress responses. Previous studies have shed light on the evolutionary trajectory of the AP2 and DREB subfamilies. However, knowledge about the evolutionary history of the ERF subfamily in angiosperms still remains limited. In this study, we performed a comprehensive analysis of the ERF subfamily from 107 representative angiosperm species by combining phylogenomic and synteny network approaches. We observed that the expansion of the ERF subfamily was driven not only by whole-genome duplication (WGD) but also by tandem duplication (TD) and transposition duplication events. We also found multiple transposition events in Poaceae, Brassicaceae, Poales, Brassicales, and Commelinids. These events may have had notable impacts on copy number variation and subsequent functional divergence of the ERF subfamily. Moreover, we observed a number of ancient tandem duplications occurred in the ERF subfamily across angiosperms, e.g., in Subgroup IX, IXb originated from ancient tandem duplication events within IXa. These findings together provide novel insights into the evolution of this important transcription factor family.

Light-induced de-etiolation is an important aspect of seedling photomorphogenesis. GOLDEN2 LIKE (GLK) transcriptional regulators are involved in chloroplast development, but to what extent they participate in photomorphogenesis is not clear. Here, we show that ELONGATED HYPOCOTYL5 (HY5) binds to GLK promoters to activate their expression, and also interacts with GLK proteins in Arabidopsis (Arabidopsis thaliana). The chlorophyll content in the de-etiolating Arabidopsis seedlings of the hy5 glk2 double mutants was lower than that in the hy5 single mutant. GLKs inhibited hypocotyl elongation, and the phenotype could superimpose on the hy5 phenotype. Correspondingly, GLK2 regulated the expression of photosynthesis and cell elongation genes partially independent of HY5. Before exposure to light, DE-ETIOLATED 1 (DET1) affected accumulation of GLK proteins. The enhanced etioplast development and photosystem gene expression observed in the det1 mutant were attenuated in the det1 glk2 double mutant. Our study reveals that GLKs act downstream of HY5, or additive to HY5, and are likely quantitatively adjusted by DET1, to orchestrate multiple developmental traits during the light-induced skotomorphogenesis-to-photomorphogenesis transition in Arabidopsis., Competing Interests: Conflict of interest statement. None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Maintaining proper metabolite levels in a complex metabolic network is crucial for maintaining a high flux through the network. In this paper, we discuss major regulatory mechanisms over the Calvin Benson Cycle (CBC) with regard to their roles in conferring homeostasis of metabolite levels in CBC. These include: 1) Redox regulation of enzymes in the CBC on one hand ensures that metabolite levels stay above certain lower bounds under low light while on the other hand increases the flux through the CBC under high light. 2) Metabolite regulations, especially allosteric regulations of major regulatory enzymes, ensure the rapid up-regulation of fluxes to ensure sufficient amount of triose phosphate is available for end product synthesis and concurrently avoid phosphate limitation. 3) A balanced activities of enzymes in the CBC help maintain balanced flux through CBC; some innate product feedback mechanisms, in particular the ADP feedback regulation of GAPDH and F6P feedback regulation of FBPase, exist in CBC to achieve such a balanced enzyme activities and hence flux distribution in the CBC for greater photosynthetic efficiency. Transcriptional regulation and natural variations of enzymes controlling CBC metabolite homeostasis should be further explored to maximize the potential of engineering CBC for greater efficiency., Competing Interests: Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Canopy photosynthesis (A c ), rather than leaf photosynthesis, is critical to gaining higher biomass production in the field because the daily or seasonal integrals of A c correlate with the daily or seasonal integrals of biomass production. The canopy photosynthesis and transpiration measurement system (CAPTS) was developed to enable measurement of canopy photosynthetic CO 2 uptake, transpiration, and respiration rates. CAPTS continuously records the CO 2 concentration, water vapor concentration, air temperature, air pressure, air relative humidity, and photosynthetic photon flux density (PPFD) inside the chamber, which can be used to derive CO 2 and H 2 O fluxes of a canopy covered by the chamber. This system can also be used to measure the fluxes of greenhouse gases when integrating with CH 4 and N 2 O analyzers. Here, we describe the protocol for using CAPTS to perform experiments on rice (Oryza sativa L.) in paddy field, wheat (Triticum aestivum L.) in upland field, and tobacco (Nicotiana tabacum L.) in pots., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

C 4 plants typically operate a CO 2 concentration mechanism from mesophyll (M) cells into bundle sheath (BS) cells. NADH dehydrogenase-like (NDH) complex is enriched in the BS cells of many NADP-malic enzyme (ME) type C 4 plants and is more abundant in C 4 than in C 3 plants, but to what extent it is involved in the CO 2 concentration mechanism remains to be experimentally investigated. We created maize and rice mutants deficient in NDH function and then used a combination of transcriptomic, proteomic, and metabolomic approaches for comparative analysis. Considerable decreases in growth, photosynthetic activities, and levels of key photosynthetic proteins were observed in maize but not rice mutants. However, transcript abundance for many cyclic electron transport (CET) and Calvin-Benson cycle components, as well as BS-specific C 4 enzymes, was increased in maize mutants. Metabolite analysis of the maize ndh mutants revealed an increased NADPH : NADP ratio, as well as malate, ribulose 1,5-bisphosphate (RuBP), fructose 1,6-bisphosphate (FBP), and photorespiration intermediates. We suggest that by optimizing NADPH and malate levels and adjusting NADP-ME activity, NDH functions to balance metabolic and redox states in the BS cells of maize (in addition to ATP supply), coordinating photosynthetic transcript abundance and protein content, thus directly regulating the carbon flow in the two-celled C 4 system of maize., (© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)

Competing Interests: Conflict of interest The authors declare that they have no conflict of interest.

Objectives: Type 2 diabetic kidney disease (DKD), a chronic microvascular complication of diabetes, may exhibit a complex interrelation with coagulation function. This study is aimed at elucidating the association between coagulation function and DKD., Methods: This was a real-world observational study conducted in Beijing, involving 2,703 participants. All patients with diabetes were classified into two groups, viz., DKD and non-DKD groups. Effect magnitudes are denoted as odds ratios (OR) with a 95% confidence interval (CI). To mitigate potential bias in group comparisons, we employed propensity score matching (PSM)., Results: After adjusting for variables such as age, gender, systolic blood pressure (SBP), hemoglobin A1c (HbA1c), triglyceride (TG), c-reactive protein (CRP), platelet (PLT), and serum albumin (sALB), it was discerned that fibrinogen (FIB) (OR, 95% CI, P : 1.565, 1.289-1.901, <0.001) and fibrinogen degradation products (FDP) (1.203, 1.077-1.344, 0.001) were significantly correlated with an increased risk of DKD. To facilitate clinical applications, a nomogram prediction model was established, demonstrating commendable accuracy for DKD prediction., Conclusions: Our findings suggest that elevated levels of FIB and FDP serve as potential risk indicators for DKD, and coagulation function may play an important role in the occurrence and development of DKD., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2023 Meng-chao Liu et al.)

The mesophyll cells of grass leaves, such as rice, are traditionally viewed as displaying a relatively uniform pattern, in contrast to the clear distinctions of palisade and spongy layers in typical eudicot leaves. This quantitative analysis of mesophyll cell size and shape in rice leaves reveals that there is an inherent pattern in which cells in the middle layer of the mesophyll are larger and less circular and have a distinct orientation of their long axis compared to mesophyll cells in other layers. Moreover, this pattern was observed in a range of rice cultivars and species. The significance of this pattern with relation to potential photosynthetic function and the implication of the widespread use of middle layer mesophyll cells as typical of the rice leaf have been investigated and discussed., Competing Interests: No conflict of interest declared., (© 2023 The Authors. Plant Direct published by American Society of Plant Biologists and the Society for Experimental Biology and John Wiley & Sons Ltd.)

Objective: We aimed to explore the association between serum complements and kidney function of diabetic kidney disease (DKD) in Chinese patients., Methods: This is a retrospective study involving 2,441 participants. DKD was diagnosed according to the Kidney Disease: Improving Global Outcomes (KDIGO) categories. Participants were classified as stages G1-G5 by KDIGO glomerular filtration rate (GFR) categories. Effect sizes are expressed as odds ratio (OR) with 95% confidence interval (CI)., Results: After balancing age, gender, systolic blood pressure (SBP), hemoglobin A1c (HbA1C), serum triglyceride (TG), and urinary albumin-to-creatinine ratio (UACR) between the G2-G5 and control groups, per 0.1 g/L increment in serum complement C3 was significantly associated with a 27.8% reduced risk of DKD at G5 stage (OR, 95% CI, P: 0.722, 0.616-0.847, <0.001) relative to the G1 stage. Conversely, per 0.1 g/L increment in serum complement C4 was associated with an 83.0-177.6% increased risk of G2-G5 stage (P<0.001). Serum complement C1q was not statistically significant compared to controls at all stages prior to or after propensity score matching., Conclusions: Our results indicate that high concentrations of serum C4 were associated with the significantly elevated risk of kidney function deterioration across all stages, and reduced serum C3 levels with an increased risk of DKD stage G5., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Li, Wang, Meng, Zheng, Cai, Shen, Wang, Zhu, Chen, Wang, Zhao, Niu and Wang.)

Terrestrial CAM plants typically occur in hot semiarid regions, yet can show high crop productivity under favorable conditions. To achieve a more mechanistic understanding of CAM plant productivity, a biochemical model of diel metabolism was developed and integrated with 3-D shoot morphology to predict the energetics of light interception and photosynthetic carbon assimilation. Using Agave tequilana as an example, this biochemical model faithfully simulated the four diel phases of CO 2 and metabolite dynamics during the CAM rhythm. After capturing the 3-D form over an 8-yr production cycle, a ray-tracing method allowed the prediction of the light microclimate across all photosynthetic surfaces. Integration with the biochemical model thereby enabled the simulation of plant and stand carbon uptake over daily and annual courses. The theoretical maximum energy conversion efficiency of Agave spp. is calculated at 0.045-0.049, up to 7% higher than for C 3 photosynthesis. Actual light interception, and biochemical and anatomical limitations, reduced this to 0.0069, or 15.6 Mg ha -1  yr -1 dry mass annualized over an 8-yr cropping cycle, consistent with observation. This is comparable to the productivity of many C 3 crops, demonstrating the potential of CAM plants in climates where little else may be grown while indicating strategies that could raise their productivity., (© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)

Objectives: The study aimed to examine the association of three anemia-related biomarkers with the adequacy of peritoneal dialysis (PD) in patients with chronic kidney disease (CKD). Methods: This study included 127 PD patients. The total Kt/V urea (Kt/V) was calculated according to the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines. All patients were classified into two groups based on Kt/V, viz., adequate (Kt/V ≥1.7) and inadequate (Kt/V <1.7) groups. Effect sizes are expressed as odds ratios (ORs) and 95% confidence interval (CI). Results: After adjusting for age, gender, hypertension, diabetes, and PD duration, 20 g/L increment in hemoglobin (Hgb) was observed to significantly reduce the risk of inadequate PD by 19% (OR; 95% CI; P: 0.81; 0.70 to 0.95; 0.009), 5 g/L increment in the mean corpuscular hemoglobin concentration (MCHC) by 7% (0.93; 0.88 to 0.98; 0.009), and 5% increment in transferrin saturation (TS) by 23% (0.77; 0.64 to 0.94; 0.012). The gender-specific nomogram model was constructed by incorporating three significant anemia-related biomarkers and convenient influencing factors, and the prediction accuracy was good (concordance index (C-index): 0.686 for men and 0.825 for women). Conclusion: Our findings indicate that the deterioration of three anemia-related biomarkers (Hgb, MCHC, and TS) can precipitate the development of inadequate PD in Chinese patients with CKD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Cai, Zhao, Zhu, Li, Li, Liu, Cui, Zhao and Niu.)

Crop yield potential is intrinsically related to canopy photosynthesis; therefore, improving canopy photosynthetic efficiency is a major focus of current efforts to enhance crop yield. Canopy photosynthesis rate ( A c ) is influenced by several factors, including plant architecture, leaf chlorophyll content, and leaf photosynthetic properties, which interact with each other. Identifying factors that restrict canopy photosynthesis and target adjustments to improve canopy photosynthesis in a specific crop cultivar pose an important challenge for the breeding community. To address this challenge, we developed a novel pipeline that utilizes factorial analysis, canopy photosynthesis modeling, and phenomics data collected using a 64-camera multi-view stereo system, enabling the dissection of the contributions of different factors to differences in canopy photosynthesis between maize cultivars. We applied this method to 2 maize varieties, W64A and A619, and found that leaf photosynthetic efficiency is the primary determinant (17.5% to 29.2%) of the difference in A c between 2 maize varieties at all stages, and plant architecture at early stages also contribute to the difference in A c (5.3% to 6.7%). Additionally, the contributions of each leaf photosynthetic parameter and plant architectural trait were dissected. We also found that the leaf photosynthetic parameters were linearly correlated with A c and plant architecture traits were non-linearly related to A c . This study developed a novel pipeline that provides a method for dissecting the relationship among individual phenotypes controlling the complex trait of canopy photosynthesis., (Copyright © 2023 Qingfeng Song et al.)

Gynandropsis gynandra (Cleomaceae) is a cosmopolitan leafy vegetable and medicinal plant, which has also been used as a model to study C4 photosynthesis due to its evolutionary proximity to C3 Arabidopsis (Arabidopsis thaliana). Here, we present the genome sequence of G. gynandra, anchored onto 17 main pseudomolecules with a total length of 740 Mb, an N50 of 42 Mb and 30,933 well-supported gene models. The G. gynandra genome and previously released genomes of C3 relatives in the Cleomaceae and Brassicaceae make an excellent model for studying the role of genome evolution in the transition from C3 to C4 photosynthesis. Our analyses revealed that G. gynandra and its C3 relative Tarenaya hassleriana shared a whole-genome duplication event (Gg-α), then an addition of a third genome (Th-α, +1×) took place in T. hassleriana but not in G. gynandra. Analysis of syntenic copy number of C4 photosynthesis-related gene families indicates that G. gynandra generally retained more duplicated copies of these genes than C3T. hassleriana, and also that the G. gynandra C4 genes might have been under positive selection pressure. Both whole-genome and single-gene duplication were found to contribute to the expansion of the aforementioned gene families in G. gynandra. Collectively, this study enhances our understanding of the polyploidy history, gene duplication and retention, as well as their impact on the evolution of C4 photosynthesis in Cleomaceae., Competing Interests: Conflict of interest statement. The authors declare no conflict of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Tillering and yield are linked in rice, with significant efforts being invested to understand the genetic basis of this phenomenon. However, in addition to genetic factors, tillering is also influenced by the environment. Exploiting experiments in which seedlings were first grown in elevated CO 2 (eCO 2 ) before transfer and further growth under ambient CO 2 (aCO 2 ) levels, we found that even moderate exposure times to eCO 2 were sufficient to induce tillering in seedlings, which was maintained in plants grown to maturity plants in controlled environment chambers. We then explored whether brief exposure to eCO 2 (eCO 2 priming) could be implemented to regulate tiller number and yield in the field. We designed a cost-effective growth system, using yeast to increase the CO 2 level for the first 24 days of growth, and grew these seedlings to maturity in semi-field conditions in Malaysia. The increased growth caused by eCO 2 priming translated into larger mature plants with increased tillering, panicle number, and improved grain filling and 1000 grain weight. In order to make the process more appealing to conventional rice farmers, we then developed a system in which fungal mycelium was used to generate the eCO 2 via respiration of sugars derived by growing the fungus on lignocellulosic waste. Not only does this provide a sustainable source of CO 2 , it also has the added financial benefit to farmers of generating economically valuable oyster mushrooms as an end-product of mycelium growth. Our experiments show that the system is capable of generating sufficient CO 2 to induce increased tillering in rice seedlings, leading eventually to 18% more tillers and panicles in mature paddy-grown crop. We discuss the potential of eCO 2 priming as a rapidly implementable, broadly applicable and sustainable system to increase tillering, and thus yield potential in rice., (© 2023. The Author(s).)

The "Father of Hybrid Rice", Yuan Longping, created high-yield hybrid rice that can feed tens of millions of people annually. The research achievements of Yuan and his team on low cadmium-accumulating rice and sea rice, in addition to hybrid rice, as well as those of a large number of Chinese scientists engaged in rice research in other six areas, including the rice genome, purple endosperm rice, de novo domestication of tetraploid rice, perennial rice, rice blast disease, and key genes for high nitrogen use efficiency, play an important role in promoting the realization of the United Nations Sustainable Development Goals 2 and 12. The purpose of this review is not to elaborate on the details of each research, but to innovatively summarize the significance and inspiration of these achievements to ensure global food security and achieve sustainable agriculture. In the future, cultivating new rice varieties through modern biotechnology, such as genome editing, will not only reduce hunger, but potentially reduce human-land conflicts, improve the environment, and mitigate climate change., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Gao and Zhu.)

Background: Biologists have long debated the drivers of the genome size evolution and variation ever since Darwin. Assumptions for the adaptive or maladaptive consequences of the associations between genome sizes and environmental factors have been proposed, but the significance of these hypotheses remains controversial. Eragrostis is a large genus in the grass family and is often used as crop or forage during the dry seasons. The wide range and complex ploidy levels make Eragrostis an excellent model for investigating how the genome size variation and evolution is associated with environmental factors and how these changes can ben interpreted., Methods: We reconstructed the Eragrostis phylogeny and estimated genome sizes through flow cytometric analyses. Phylogenetic comparative analyses were performed to explore how genome size variation and evolution is related to their climatic niches and geographical ranges. The genome size evolution and environmental factors were examined using different models to study the phylogenetic signal, mode and tempo throughout evolutionary history., Results: Our results support the monophyly of Eragrostis . The genome sizes in Eragrostis ranged from ~0.66 pg to ~3.80 pg. We found that a moderate phylogenetic conservatism existed in terms of the genome sizes but was absent from environmental factors. In addition, phylogeny-based associations revealed close correlations between genome sizes and precipitation-related variables, indicating that the genome size variation mainly caused by polyploidization may have evolved as an adaptation to various environments in the genus Eragrostis ., Conclusion: This is the first study to take a global perspective on the genome size variation and evolution in the genus Eragrostis . Our results suggest that the adaptation and conservatism are manifested in the genome size variation, allowing the arid species of Eragrostis to spread the xeric area throughout the world., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Hutang, Tong, Zhu and Gao.)

Weed species are detrimental to crop yield. An understanding of how weeds originate and adapt to field environments is needed for successful crop management and reduction of herbicide use. Although early flowering is one of the weed trait syndromes that enable ruderal weeds to overcome frequent disturbances, the underlying genetic basis is poorly understood. Here, we establish Cardamine occulta as a model to study weed ruderality. By genome assembly and QTL mapping, we identify impairment of the vernalization response regulator gene FLC and a subsequent dominant mutation in the blue-light receptor gene CRY2 as genetic drivers for the establishment of short life cycle in ruderal weeds. Population genomics study further suggests that the mutations in these two genes enable individuals to overcome human disturbances through early deposition of seeds into the soil seed bank and quickly dominate local populations, thereby facilitating their spread in East China. Notably, functionally equivalent dominant mutations in CRY2 are shared by another weed species, Rorippa palustris, suggesting a common evolutionary trajectory of early flowering in ruderal weeds in Brassicaceae., (© 2023. The Author(s).)

C 4 photosynthesis evolved from ancestral C 3 photosynthesis by recruiting pre-existing genes to fulfill new functions. The enzymes and transporters required for the C 4 metabolic pathway have been intensively studied and well documented; however, the transcription factors (TFs) that regulate these C 4 metabolic genes are not yet well understood. In particular, how the TF regulatory network of C 4 metabolic genes was rewired during the evolutionary process is unclear. Here, we constructed gene regulatory networks (GRNs) for four closely evolutionarily related species from the genus Flaveria, which represent four different evolutionary stages of C 4 photosynthesis: C 3 (F. robusta), type I C 3 -C 4 (F. sonorensis), type II C 3 -C 4 (F. ramosissima), and C 4 (F. trinervia). Our results show that more than half of the co-regulatory relationships between TFs and core C 4 metabolic genes are species specific. The counterparts of the C 4 genes in C 3 species were already co-regulated with photosynthesis-related genes, whereas the required TFs for C 4 photosynthesis were recruited later. The TFs involved in C 4 photosynthesis were widely recruited in the type I C 3 -C 4 species; nevertheless, type II C 3 -C 4 species showed a divergent GRN from C 4 species. In line with these findings, a 13 CO 2 pulse-labeling experiment showed that the CO 2 initially fixed into C 4 acid was not directly released to the Calvin-Benson-Bassham cycle in the type II C 3 -C 4 species. Therefore, our study uncovered dynamic changes in C 4 genes and TF co-regulation during the evolutionary process; furthermore, we showed that the metabolic pathway of the type II C 3 -C 4 species F. ramosissima represents an alternative evolutionary solution to the ammonia imbalance in C 3 -C 4 intermediate species., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Flaveria is a leading model for C4 plant evolution due to the presence of a dozen C3-C4 intermediate species, many of which are associated with a phylogenetic complex centered around Flaveria linearis. To investigate C4 evolution in Flaveria, we updated the Flaveria phylogeny and evaluated gas exchange, starch δ13C, and activity of C4 cycle enzymes in 19 Flaveria species and 28 populations within the F. linearis complex. A principal component analysis identified six functional clusters: (1) C3, (2) sub-C2, (3) full C2, (4) enriched C2, (5) sub-C4, and (6) fully C4 species. The sub-C2 species lacked a functional C4 cycle, while a gradient was present in the C2 clusters from little to modest C4 cycle activity as indicated by δ13C and enzyme activities. Three Yucatan populations of F. linearis had photosynthetic CO2 compensation points equivalent to C4 plants but showed little evidence for an enhanced C4 cycle, indicating they have an optimized C2 pathway that recaptures all photorespired CO2 in the bundle sheath (BS) tissue. All C2 species had enhanced aspartate aminotransferase activity relative to C3 species and most had enhanced alanine aminotransferase activity. These aminotransferases form aspartate and alanine from glutamate and in doing so could help return photorespiratory nitrogen (N) from BS to mesophyll cells, preventing glutamate feedback onto photorespiratory N assimilation. Their use requires upregulation of parts of the C4 metabolic cycle to generate carbon skeletons to sustain N return to the mesophyll, and thus could facilitate the evolution of the full C4 photosynthetic pathway., (© American Society of Plant Biologists 2022. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Leaf structure plays an important role in photosynthesis. However, the causal relationship and the quantitative importance of any single structural parameter to the overall photosynthetic performance of a leaf remains open to debate. In this paper, we report on a mechanistic model, eLeaf, which successfully captures rice leaf photosynthetic performance under varying environmental conditions of light and CO 2 . We developed a 3D reaction-diffusion model for leaf photosynthesis parameterised using a range of imaging data and biochemical measurements from plants grown under ambient and elevated CO 2 and then interrogated the model to quantify the importance of these elements. The model successfully captured leaf-level photosynthetic performance in rice. Photosynthetic metabolism underpinned the majority of the increased carbon assimilation rate observed under elevated CO 2 levels, with a range of structural elements making positive and negative contributions. Mesophyll porosity could be varied without any major outcome on photosynthetic performance, providing a theoretical underpinning for experimental data. eLeaf allows quantitative analysis of the influence of morphological and biochemical properties on leaf photosynthesis. The analysis highlights a degree of leaf structural plasticity with respect to photosynthesis of significance in the context of attempts to improve crop photosynthesis., (© 2022 The Authors New Phytologist © 2022 New Phytologist Foundation.)

Background: Acute pancreatitis (AP) is a complex and heterogeneous disease. We aimed to design and validate a prognostic nomogram for improving the prediction of short-term survival in patients with AP., Methods: The clinical data of 632 patients with AP were obtained from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The nomogram for the prediction of 30-day, 60-day and 90-day survival was developed by incorporating the risk factors identified by multivariate Cox analyses., Results: Multivariate Cox proportional hazard model analysis showed that age (hazard ratio [HR]=1.06, 95% confidence interval [95% CI] 1.03-1.08, P<0.001), white blood cell count (HR=1.03, 95% CI 1.00-1.06, P=0.046), systolic blood pressure (HR=0.99, 95% CI 0.97-1.00, P=0.015), serum lactate level (HR=1.10, 95% CI 1.01-1.20, P=0.023), and Simplified Acute Physiology Score II (HR=1.04, 95% CI 1.02-1.06, P<0.001) were independent predictors of 90-day mortality in patients with AP. A prognostic nomogram model for 30-day, 60-day, and 90-day survival based on these variables was built. Receiver operating characteristic (ROC) curve analysis demonstrated that the nomogram had good accuracy for predicting 30-day, 60-day, and 90-day survival (area under the ROC curve: 0.796, 0.812, and 0.854, respectively; bootstrap-corrected C-index value: 0.782, 0.799, and 0.846, respectively)., Conclusion: The nomogram-based prognostic model was able to accurately predict 30-day, 60-day, and 90-day survival outcomes and thus may be of value for risk stratification and clinical decision-making for critically ill patients with AP., Competing Interests: Conflicts of interest: The authors report that there are no competing interests to declare., (Copyright: © World Journal of Emergency Medicine.)

100-120 words. References should not be included. Abbreviations should be avoided as far as possible. Low stomatal conductance (g s ) poses a major constraint for improving photosynthetic efficiency for greater yield. Options at the molecular, leaf, canopy, and even the whole plant scales can be developed to enhance g s for greater light and water use efficiencies. Among these, many genes regulating stomatal development and stomatal movement have been discovered and manipulated to increase light and water use efficiencies under well-watered, drought, or facility agriculture conditions with the manual-controlled growth environmental. Optimization of canopy conductance to increase whole plant photosynthesis with full consideration of the heterogeneities in g s , microclimates and leaf ontology inside the canopy represents a largely uncharted area to improve crop efficiency., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Knowledge about the prognostic role of long noncoding RNA (lncRNA) in colorectal cancer (CRC) is limited. Therefore, we constructed a lncRNA-related prognostic model based on data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). Materials and Methods: CRC transcriptome and clinical data were downloaded from the GSE20916 dataset and the TCGA database, respectively. R software was used for data processing and analysis. The differential lncRNA expression within the two datasets was first screened, and then intersections were measured. Cox regression and the Kaplan-Meier method were used to evaluate the effects of various factors on prognosis. The area under the curve (AUC) of the receiver operating characteristic curve and a nomogram based on multivariate Cox analysis were used to estimate the prognostic value of the lncRNA-related model. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were applied to elucidate the significantly involved biological functions and pathways. Results: A total of 11 lncRNAs were crossed. The univariate Cox analysis screened out two lncRNAs, which were analyzed in the multivariate Cox analysis. A nomogram based on the two lncRNAs and other clinicopathological risk factors was constructed. The AUC of the nomogram was 0.56 at 3 years and 0.71 at 5 years. The 3-year nomogram model was compared with the ideal model, which showed that some indices of the 3-year model were consistent with the ideal model, suggesting that our model was highly accurate. The GO and KEGG enrichment analyses showed that positive regulation of secretion by cells, positive regulation of secretion, positive regulation of exocytosis, endocytosis, and the calcium signaling pathway were differentially enriched in the two-lncRNA-associated phenotype. Conclusions: A two-lncRNA prognostic model of CRC was constructed by bioinformatics analysis. The model had moderate prediction accuracy. LncRNA BBOX1-AS1 and lncRNA FOXP4-AS1 were identified as prognostic biomarkers.

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Background: The effects of consolidation chemotherapy (CC) in neoadjuvant therapy in locally advanced rectal cancer (LARC) have been explored. However, the optimal neoadjuvant chemoradiotherapy (NCRT) and surgery interval, regimen, and cycles of chemotherapy remains unclear., Aim: To evaluate the effects of one to two cycles of CC with capecitabine on high-risk patients with LARC without extending NCRT and surgery interval., Methods: We retrospectively evaluated high-risk patients with LARC, who were defined as having at least one of the following factors by magnetic resonance imaging: depth of invasion beyond the muscularis propria of more than 5 mm (cT3c-cT3d), T4, meso-rectal fascia or extramural vascular invasion positive, and treatment date between January 2015 and July 2019 in our center. Patients were divided into the CC and non-CC group according to whether they received CC (capecitabine 1000 mg/m 2 twice daily from days 1 to 14 every 21 d) after NCRT. Propensity score matching (PSM) and inverse probability of treatment weight (IPTW) were used to balance the differences between the two groups. The main outcome was the complete response (CR) rate., Results: A total of 265 patients were enrolled: 136 patients in the CC group and 129 patients in the non-CC group. The median interval was 70 d (range, 37-168). The CR rate was 24.3% and 16.3% ( P = 0.107) in the CC and non-CC groups' original samples, respectively. After PSM and IPTW, the CR rate in the CC group was higher than that in non-CC group (27.6% vs 16.2%, P = 0.045; 25.9% vs 16.3%, P = 0.045). The median follow-up was 39.8 mo (range, 2.9-74.8), and there were no differences in 3-year non-regrowth disease-free survival nor overall survival in the original samples (73.2% vs 71.9%, P = 0.913; 92.3% vs 86.7%, P = 0.294), PSM (73.2% vs 73.5%, P = 0.865; 92.5% vs 89.3%, P = 0.612), and IPTW (73.8% vs 72.1%, P = 0.913; 92.4% vs 87.4%, P = 0.294). There was also no difference in grade 2 or higher acute toxicity during neoadjuvant therapy in the two groups (49.3% vs 53.5%, P = 0.492)., Conclusion: One to two cycles of CC with capecitabine after NCRT was safe and increased the CR rate in high-risk LARC but failed to improve the long-term outcomes., Competing Interests: Conflict-of-interest statement: All authors report no relevant conflict of interest for this article., (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)

C4 photosynthesis optimizes plant carbon and water relations, allowing high photosynthetic rates with low stomatal conductance. Stomata have long been considered a part of the C4 syndrome. However, it remains unclear how stomatal traits evolved along the path from C3 to C4. Here, we examined stomata in the Flaveria genus, a model used for C4 evolutionary study. Comparative, transgenic, and semi-in vitro experiments were performed to study the molecular basis that underlies the changes of stomatal traits in C4 evolution. The evolution from C3 to C4 species is accompanied by a gradual rather than an abrupt change in stomatal traits. The initial change appears near the Type I intermediate stage. Co-evolution of the photosynthetic pathway and stomatal traits is supported. On the road to C4, stomata tend to be fewer in number but larger in size and stomatal density dominates changes in anatomical maximum stomatal conductance (gsmax). Reduction of FSTOMAGEN expression underlies decreased gsmax in Flaveria and likely occurs in other C4 lineages. Decreased gsmax contributes to the increase in intrinsic water-use efficiency in C4 evolution. This work highlights the stomatal traits in the current C4 evolutionary model. Our study provides insights into the pattern, mechanism, and role of stomatal evolution along the road toward C4., (© American Society of Plant Biologists 2022. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The rate of algal and cyanobacterial respiration in the light is an important ecophysiological term that remains to be completely characterized and quantified. To address this issue, we exploited process-specific decarboxylation rates from flux balance analysis and isotopically nonstationary metabolic flux analysis. Our study, based on published data, suggested that decarboxylation is about 22% of net CO2 assimilation when the tricarboxylic acid cycle is completely open (characterized by the commitment of alpha ketoglutarate to amino acid synthesis and very low rates of succinate formation). This estimate was supported by calculating the decarboxylation rates required to synthesize the major components of biomass (proteins, lipids, and carbohydrates) at their typical abundance. Of the 22 CO2 molecules produced by decarboxylation (normalized to net assimilation = 100), approximately 13 were from pyruvate and 3 were from isocitrate. The remaining six units of decarboxylation were in the amino acid synthesis pathways outside the tricarboxylic acid cycle. A small additional flux came from photorespiration, decarboxylations of six phosphogluconate in the oxidative pentose phosphate pathway, and decarboxylations in the syntheses of lower-abundance compounds, including pigments and ribonucleic acids. This general approach accounted for the high decarboxylation rates in algae and cyanobacteria compared to terrestrial plants. It prompts a simple speculation for the origin of the Kok effect and helps constrain the photoautotrophic respiration rate, in the light, in the euphotic zone of the ocean and lakes., (© The Author(s) 2022. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Canopy photosynthesis is the sum of photosynthesis of all above-ground photosynthetic tissues. Quantitative roles of nonfoliar tissues in canopy photosynthesis remain elusive due to methodology limitations. Here, we develop the first complete canopy photosynthesis model incorporating all above-ground photosynthetic tissues and validate this model on wheat with state-of-the-art gas exchange measurement facilities. The new model precisely predicts wheat canopy gas exchange rates at different growth stages, weather conditions, and canopy architectural perturbations. Using the model, we systematically study (1) the contribution of both foliar and nonfoliar tissues to wheat canopy photosynthesis and (2) the responses of wheat canopy photosynthesis to plant physiological and architectural changes. We found that (1) at tillering, heading, and milking stages, nonfoliar tissues can contribute ~4, ~32, and ~50% of daily gross canopy photosynthesis ( A cgross ; ~2, ~15, and ~-13% of daily net canopy photosynthesis, A cnet ) and absorb ~6, ~42, and ~60% of total light, respectively; (2) under favorable condition, increasing spike photosynthetic activity, rather than enlarging spike size or awn size, can enhance canopy photosynthesis; (3) covariation in tissue respiratory rate and photosynthetic rate may be a major factor responsible for less than expected increase in daily A cnet ; and (4) in general, erect leaves, lower spike position, shorter plant height, and proper plant densities can benefit daily A cnet . Overall, the model, together with the facilities for quantifying plant architecture and tissue gas exchange, provides an integrated platform to study canopy photosynthesis and support rational design of photosynthetically efficient wheat crops., Competing Interests: The authors declare no competing financial interests., (Copyright © 2022 Tian-Gen Chang et al.)

Genome size variation and evolutionary forces behind have been long pursued in flowering plants. The genus Oryza , consisting of approximately 25 wild species and two cultivated rice, harbors eleven extant genome types, six of which are diploid (AA, BB, CC, EE, FF, and GG) and five of which are tetraploid (BBCC, CCDD, HHJJ, HHKK, and KKLL). To obtain the most comprehensive knowledge of genome size variation in the genus Oryza , we performed flow cytometry experiments and estimated genome sizes of 166 accessions belonging to 16 non-AA genome Oryza species. k -mer analyses were followed to verify the experimental results of the two accessions for each species. Our results showed that genome sizes largely varied fourfold in the genus Oryza , ranging from 279 Mb in Oryza brachyantha (FF) to 1,203 Mb in Oryza ridleyi (HHJJ). There was a 2-fold variation (ranging from 570 to 1,203 Mb) in genome size among the tetraploid species, while the diploid species had 3-fold variation, ranging from 279 Mb in Oryza brachyantha (FF) to 905 Mb in Oryza australiensis (EE). The genome sizes of the tetraploid species were not always two times larger than those of the diploid species, and some diploid species even had larger genome sizes than those of tetraploids. Nevertheless, we found that genome sizes of newly formed allotetraploids (BBCC-) were almost equal to totaling genome sizes of their parental progenitors. Our results showed that the species belonging to the same genome types had similar genome sizes, while genome sizes exhibited a gradually decreased trend during the evolutionary process in the clade with AA, BB, CC, and EE genome types. Comparative genomic analyses further showed that the species with different rice genome types may had experienced dissimilar amplification histories of retrotransposons, resulting in remarkably different genome sizes. On the other hand, the closely related rice species may have experienced similar amplification history. We observed that the contents of transposable elements, long terminal repeats (LTR) retrotransposons, and particularly LTR/ Gypsy retrotransposons varied largely but were significantly correlated with genome sizes. Therefore, this study demonstrated that LTR retrotransposons act as an active driver of genome size variation in the genus Oryza ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Dai, Zhu, Hutang, Li, Tian, Jiang, Zhang and Gao.)

Photosystem II (PSII), which splits water molecules at minimal excess photochemical potential, is inevitably photoinactivated during photosynthesis, resulting in compromised photosynthetic efficiency unless it is repaired. The energy cost of PSII repair is currently uncertain, despite attempts to calculate it. We experimentally determined the energy cost of repairing each photoinactivated PSII in cotton (Gossypium hirsutum) leaves, which are capable of repairing PSII in darkness. As an upper limit, 24 000 adenosine triphosphate (ATP) molecules (including any guanosine triphosphate synthesized at the expense of ATP) were required to repair one entire PSII complex. Further, over a 7-h illumination period at 526-1953 μmol photons m -2  s -1 , the ATP requirement for PSII repair was on average up to 4.6% of the ATP required for the gross carbon assimilation. Each of these two measures of ATP requirement for PSII repair is two- to three-fold greater than the respective reported calculated value. Possible additional energy sinks in the PSII repair cycle are discussed., (© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation.)

Background: Accurate target volume delineation is the premise for the implementation of precise radiotherapy. Inadequate target volume delineation may diminish tumor control or increase toxicity. Although several clinical target volume (CTV) delineation guidelines for rectal cancer have been published in recent years, significant interobserver variation (IOV) in CTV delineation still exists among radiation oncologists. However, proper education may serve as a bridge that connects complex guidelines with clinical practice., Aim: To examine whether an education program could improve the accuracy and consistency of preoperative radiotherapy CTV delineation for rectal cancer., Methods: The study consisted of a baseline target volume delineation, a 150-min education intervention, and a follow-up evaluation. A 42-year-old man diagnosed with stage IIIC (T3N2bM0) rectal adenocarcinoma was selected for target volume delineation. CTVs obtained before and after the program were compared. Dice similarity coefficient (DSC), inclusiveness index (IncI), conformal index (CI), and relative volume difference [ΔV (%)] were analyzed to quantitatively evaluate the disparities between the participants' delineation and the standard CTV. Maximum volume ratio (MVR) and coefficient of variation (CV) were calculated to assess the IOV. Qualitative analysis included four common controversies in CTV delineation concerning the upper boundary of the target volume, external iliac area, groin area, and ischiorectal fossa., Results: Of the 18 radiation oncologists from 10 provinces in China, 13 completed two sets of CTVs. In quantitative analysis, the average CTV volume decreased from 809.82 cm 3 to 705.21 cm 3 ( P = 0.001) after the education program. Regarding the indices for geometric comparison, the mean DSC, IncI, and CI increased significantly, while ΔV (%) decreased remarkably, indicating improved agreement between participants' delineation and the standard CTV. Moreover, an 11.80% reduction in MVR and 18.19% reduction in CV were noted, demonstrating a smaller IOV in delineation after the education program. Regarding qualitative analysis, the greatest variations in baseline were observed at the external iliac area and ischiorectal fossa; 61.54% (8/13) and 53.85% (7/13) of the participants unnecessarily delineated the external iliac area and the ischiorectal fossa, respectively. However, the education program reduced these variations., Conclusion: Wide variations in CTV delineation for rectal cancer are present among radiation oncologists in mainland China. A well-structured education program could improve delineation accuracy and reduce IOVs., Competing Interests: Conflict-of-interest statement: The authors declare that there is no conflict of interest., (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)

Compared to the large number of studies focused on the factors controlling C3 photosynthesis efficiency, there are relatively fewer studies of the factors controlling photosynthetic efficiency in C4 leaves. Here, we used a dynamic systems model of C4 photosynthesis based on maize (Zea mays) to identify features associated with high photosynthetic efficiency in NADP-malic enzyme (NADP-ME) type C4 photosynthesis. We found that two additional factors related to coordination between C4 shuttle metabolism and C3 metabolism are required for efficient C4 photosynthesis: (1) accumulating a high concentration of phosphoenolpyruvate through maintaining a large PGA concentration in the mesophyll cell chloroplast and (2) maintaining a suitable oxidized status in bundle sheath cell chloroplasts. These identified mechanisms are in line with the current cellular location of enzymes/proteins involved in the starch synthesis, the Calvin-Benson cycle and photosystem II of NADP-ME type C4 photosynthesis. These findings suggested potential strategies for improving C4 photosynthesis and engineering C4 rice., (© The Author(s) 2022. Published by Oxford University Press on behalf of American Society of Plant Biologists.)

Objective: To investigate the clinical effect of focused ultrasound ablation surgery (FUAS) combined with suction curettage for mass-type cesarean scar pregnancy (CSP) and to analyze the influencing factors of vaginal bleeding and readmission. Methods: From January 2014 to December 2020, 88 patients with mass-type CSP were treated by FUAS combined with suction curettage in the Third Xiangya Hospital of Central South University. The clinical results and the influencing factors of bleeding and readmission for mass-type CSP were analyzed. Results: All the patients underwent one time FUAS treatment successfully. Immediately after FUAS treatment, color Doppler ultrasound showed obvious necrosis and no perfusion area in all lesions, and the blood flow in the mass-type CSP tissue significantly decreased. The median volume of blood loss in the procedure was 20 ml (range: 5-950 ml). Thirteen patients (15%, 13/88) had vaginal bleeding≥200 ml, and 15 patients (17%, 15/88) were hospitalized again. The average time for menstruation recovery was (28±8) days (range: 18-66 days). The average time needed for serum human chorionic gonadotropin-beta subunit to return to normal levels was (22±6) days (range: 7-59 days). The risk of large vaginal bleeding of patients were related to the blood supply of the mass ( OR =5.280, 95% CI : 1.335-20.858, P =0.018) and the largest diameter of the mass ( OR =1.060, 95% CI : 1.010-1.120, P =0.030). The risk of readmission were related to the largest diameter of the mass ( OR =1.055, 95% CI : 1.005-1.108, P =0.030) and the depth of the uterus cavity ( OR =1.583, 95% CI : 1.015-2.471, P =0.043). No serious complications such as intestinal and nerve injury occurred during and after FUAS treatment. Conclusions: FUAS combined with suction curettage is safe and effective in treating patients with mass-type CSP through this preliminary study. The volume of vaginal bleeding are associated with the blood supply of the mass and the largest diameter of the mass, the risk of readmission are related to the largest diameter of the mass and the depth of the uterus cavity.