Molecular mechanism of internode elongation in rice.

Rice plants that form ventilated tissues, such as aerenchyma in the leaves, stems, and roots, allow for growth in waterlogged conditions (paddy fields), but they cannot breathe and drown in flooded environments where the whole plant body is submerged. However, deepwater rice plants grown in flood-prone areas of Southeast Asia survive in prolonged flooded environments by taking in air through an elongated stem (internode) and leaves that emerge above the water surface, even if the water level is several meters high and flooding continues for several months. Although it has been known that plant hormones, such as ethylene and gibberellins, promote internode elongation in deepwater rice plants, the genes that control rapid internode elongation during submergence have not been identified. We recently identified several genes responsible for the quantitative trait loci involved in internode elongation in deepwater rice. Identification of the the genes revealed a molecular gene network from ethylene to gibberellins in which internode elongation is promoted by novel ethylene-responsive factors and enhances gibberellin responsiveness at the internode. In addition, elucidation of the molecular mechanism of internode elongation in deepwater rice will help our understanding of the internode elongation mechanism in normal paddy rice and contribute to improving crops through the regulation of internode elongation.

Can the Wild Perennial, Rhizomatous Rice Species Oryza longistaminata be a Candidate for De Novo Domestication?

As climate change intensifies, the development of resilient rice that can tolerate abiotic stresses is urgently needed. In nature, many wild plants have evolved a variety of mechanisms to protect themselves from environmental stresses. Wild relatives of rice may have abundant and virtually untapped genetic diversity and are an essential source of germplasm for the improvement of abiotic stress tolerance in cultivated rice. Unfortunately, the barriers of traditional breeding approaches, such as backcrossing and transgenesis, make it challenging and complex to transfer the underlying resilience traits between plants. However, de novo domestication via genome editing is a quick approach to produce rice with high yields from orphans or wild relatives. African wild rice, Oryza longistaminata, which is part of the AA-genome Oryza species has two types of propagation strategies viz. vegetative propagation via rhizome and seed propagation. It also shows tolerance to multiple types of abiotic stress, and therefore O. longistaminata is considered a key candidate of wild rice for heat, drought, and salinity tolerance, and it is also resistant to lodging. Importantly, O. longistaminata is perennial and propagates also via rhizomes both of which are traits that are highly valuable for the sustainable production of rice. Therefore, O. longistaminata may be a good candidate for de novo domestication through genome editing to obtain rice that is more climate resilient than modern elite cultivars of O. sativa.

X-ray crystallographic and mutational analysis of the NylC precursor: catalytic mechanism of autocleavage and substrate hydrolysis of nylon hydrolase.

Nylon hydrolase (NylC), a member of the N-terminal nucleophile (Ntn) hydrolase superfamily, is responsible for the degradation of various aliphatic nylons, including nylon-6 and nylon-66. NylC is initially expressed as an inactive precursor (36 kDa), but the precursor is autocatalytically cleaved at Asn266/Thr267 to generate an active enzyme composed of 27 and 9 kDa subunits. We isolated various mutants with amino acid changes at the catalytic centre. X-ray crystallographic analysis revealed that the NylC precursor forms a doughnut-shaped quaternary structure composed of four monomers (molecules A-D) with D2 symmetry. Catalytic residues in the precursor are covered by loop regions at the A/B interface (equivalent to the C/D interface). However, the catalytic residues are exposed to the solvent environment through autocleavage followed by movements of the loop regions. T267A, D306A and D308A mutations resulted in a complete loss of autocleavage. By contrast, in the T267S mutant, autocleavage proceeded slowly at a constant reaction rate (k = 2.8 × 10-5  s-1 ) until complete conversion, but the reaction was inhibited by K189A and N219A mutations. Based on the crystallographic and molecular dynamic simulation analyses, we concluded that the Asp308-Asp306-Thr267 triad, resembling the Glu-Ser-Ser triad conserved in Ntn-hydrolase family enzymes, is responsible for autocleavage and that hydrogen-bonding networks connecting Thr267 with Lys189 and Asn219 are required for increasing the nucleophilicity of Thr267-OH in both the water accessible and water inaccessible systems. Furthermore, we determined that NylC employs the Asp308-Asp306-Thr267 triad as catalytic residues for substrate hydrolysis, but the reaction requires Lys189 and Tyr146 as additional catalytic/substrate-binding residues specific for nylon hydrolysis.

Regulator of Awn Elongation 3, an E3 ubiquitin ligase, is responsible for loss of awns during African rice domestication.

Two species of rice have been independently domesticated from different ancestral wild species in Asia and Africa. Comparison of mutations that underlie phenotypic and physiological alterations associated with domestication traits in these species gives insights into the domestication history of rice in both regions. Asian cultivated rice, Oryza sativa, and African cultivated rice, Oryza glaberrima, have been modified and improved for common traits beneficial for humans, including erect plant architecture, nonshattering seeds, nonpigmented pericarp, and lack of awns. Independent mutations in orthologous genes associated with these traits have been documented in the two cultivated species. Contrary to this prevailing model, selection for awnlessness targeted different genes in O. sativa and O. glaberrima. We identify Regulator of Awn Elongation 3 (RAE3) a gene that encodes an E3 ubiquitin ligase and is responsible for the awnless phenotype only in O. glaberrima. A 48-bp deletion may disrupt the substrate recognition domain in RAE3 and diminish awn elongation. Sequencing analysis demonstrated low nucleotide diversity in a ~600-kb region around the derived rae3 allele on chromosome 6 in O. glaberrima compared with its wild progenitor. Identification of RAE3 sheds light on the molecular mechanism underlying awn development and provides an example of how selection on different genes can confer the same domestication phenotype in Asian and African rice.

Risk Factors Associated with Clinical Failure of Uterine Artery Embolization for Postpartum Hemorrhage.

PURPOSE: To identify risk factors for clinical failure of uterine artery embolization (UAE) for postpartum hemorrhage (PPH), with particular attention to the uterine artery diameter. MATERIALS AND METHODS: This retrospective study included 47 patients who underwent UAE for PPH between January 1, 2010, and January 31, 2021. Technical success was defined as the completion of embolization of the arteries thought to be the cause of the bleeding. Clinical success was defined as no recurrent bleeding or need for additional therapeutic interventions. Univariate and multivariate analyses were performed to examine the risk factors associated with clinical failure of UAE. RESULTS: Of the 47 patients, 6 had recurrent bleeding. Of the 6 patients, 4 underwent hysterectomy, and 2 underwent repeat embolization. The clinical success rate was 87.2% (41/47), with no major adverse events such as uterine infarction or death. In univariate analysis, there were slight differences in multiparity (P = .115) and placental abruption (P = .128) and a significant difference in the findings of a narrow uterine artery on digital subtraction angiography (DSA) (P = .005). In multivariate analysis, only a narrow uterine artery on DSA was a significant factor (odds ratio, 18.5; 95% confidence interval, 2.5-134.8; P = .004). CONCLUSIONS: A narrow uterine artery on DSA was a risk factor for clinically unsuccessful UAE for PPH. It may be prudent to conclude the procedure only after it is ensured that vasospasm has been relieved.

Percutaneous sclerotherapy with OK-432 for lymphocele after pelvic or para-aortic lymphadenectomy: preliminary results.

BACKGROUND: Lymphoceles can result from disruption of lymphatic vessels after surgical procedures in areas with extensive lymphatic networks. Percutaneous catheter drainage with sclerotherapy can be performed for the treatment of lymphoceles. OK-432 has been used to treat benign cysts, such as lymphangioma and ranula. Therefore, we aimed to report the efficacy and safety of sclerotherapy using OK-432 for postoperative lymphoceles. This study retrospectively analyzed 16 patients who underwent sclerotherapy using OK-432 for postoperative pelvic and para-aortic lymphoceles between April 1, 2012, and March 31, 2020. All the patients underwent percutaneous drainage before sclerotherapy. The indications for sclerotherapy were persistent drainage tube output of greater than 50 mL per day and recurrent lymphoceles after percutaneous drainage. If less than 20 mL per day was drained after sclerotherapy, the tube was removed. When the drainage tube output did not decrease to less than 20 mL per day after the first sclerotherapy, the second sclerotherapy was performed 1 week later. Technical success was defined as the completion of drainage and sclerotherapy procedures. Clinical success was defined as the resolution of the patient's symptoms resulting from lymphoceles without surgical intervention. This study also evaluated the complications of sclerotherapy and their progress after sclerotherapy. RESULTS: The mean initial lymphocele size and drainage duration after sclerotherapy were 616 mL and 7.1 days, respectively. The technical success rate and clinical success rate were 100% and 93%, respectively. Thirteen patients were treated by one-session sclerotherapy and three patients were treated by two-session sclerotherapy. Minor complications (fever) were observed in eight patients (50%). A major complication (small bowel fistula) was observed in one patient (7%). No recurrence of lymphoceles was observed during the mean follow-up period of 17 months. CONCLUSION: Sclerotherapy with OK-432 is an effective therapeutic method for postoperative lymphoceles. Although most complications are minor, a small bowel fistula was observed in one patient.

Deep Fluorescence Observation in Rice Shoots via Clearing Technology.

The recently developed clearing technology that eliminates refractive index mismatches and diminishes auto-fluorescent material has made it possible to observe plant tissues in three dimensions (3D) while preserving their internal structures. In rice (Oryza sativa L.), a monocot model plant and a globally important crop, clearing technology has been reported in organs that are relatively easy to observe, such as the roots and leaves. Applications of clearing technology in shoot apical meristem (SAM) and stems have also been reported, but only to a limited degree because of the poor penetration of the clearing solution (CS) in these tissues. The limited efficiency of the clearing solutions in these tissues has been attributed to auto-fluorescence, thickening, and hardening of the tissues in the stem as the vascular bundles and epidermis develop and layering of the SAM with water-repellent leaves. The present protocol reports the optimization of a clearing approach for continuous and 3D observation of gene expression from the SAM/young panicle to the base of the shoots during development. Fixed tissue samples expressing a fluorescent protein reporter were trimmed into sections using a vibrating micro-slicer. When an appropriate thickness was achieved, the CS was applied. By specifically targeting the central tissue, the penetration rate and uniformity of the CS increased, and the time required to make the tissue transparent decreased. Additionally, clearing of the trimmed sections enabled the observation of the internal structure of the whole shoot from a macro perspective. This method has potential applications in deep imaging of tissues of other plant species that are difficult to clear.

SNORKEL Genes Relating to Flood Tolerance Were Pseudogenized in Normal Cultivated Rice.

SNORKEL1 (SK1) and SNORKEL2 (SK2) are ethylene responsive factors that regulate the internode elongation of deepwater rice in response to submergence. We previously reported that normal cultivated rice lacks SK genes because the Chromosome 12 region containing SK genes was deleted from its genome. However, no study has analyzed how the genome defect occurred in that region by comparing normal cultivated rice and deepwater rice. In this study, comparison of the sequence of the end of Chromosome 12, which contains SK genes, between normal and deepwater rice showed that complicated genome changes such as insertions, deletions, inversions, substitutions, and translocation occurred frequently in this region. In addition to SK1 and SK2 of deepwater rice, gene prediction analysis identified four genes containing AP2/ERF domains in normal cultivated rice and six in deepwater rice; we called these genes SK-LIKE (SKL) genes. SKs and SKLs were present in close proximity to each other, and the SKLs in normal cultivated rice were in tandem. These predicted genes belong to the same AP2/ERF subfamily and were separated into four types: SK1, SK2, SKL3, and SKL4. Sequence comparison indicated that normal cultivated rice possesses a gene with high homology to SK2, which we named SKL1. However, none of the predicted SKLs except for SKL3s were expressed during submergence. Although SKL3s were expressed in both normal and deepwater rice, normal rice does not undergo internode elongation, suggesting that its expression does not contribute to internode elongation. Plants overexpressing SKL1, which showed the most homology to SK2, underwent internode elongation similar to plants overexpressing SK1 and SK2 under normal growth conditions. A yeast one-hybrid assay showed that the C-end of SKL1 has transcription activity, as do the C-ends of SK1 and SK2. Our results suggested that SKLs were derived via gene duplication, but were not expressed and pseudogenized in normal cultivated rice during sequence evolution.

Noninvasive imaging of hollow structures and gas movement revealed the gas partial-pressure-gradient-driven long-distance gas movement in the aerenchyma along the leaf blade to submerged organs in rice.

Rice (Oryza sativa) plants have porous or hollow organs consisting of aerenchyma, which is presumed to function as a low-resistance diffusion pathway for air to travel from the foliage above the water to submerged organs. However, gas movement in rice plants has yet to be visualized in real time. In this study involving partially submerged rice plants, the leaves emerging from the water were fed nitrogen-13-labeled nitrogen ([13 N]N2 ) tracer gas, and the gas movement downward along the leaf blade, leaf sheath, and internode over time was monitored. The [13 N]N2 gas arrived at the bottom of the plant within 10 min, which was 20 min earlier than carbon-11 photoassimilates. The [13 N]N2 gas movement was presumably mediated by diffusion along the aerenchyma network from the leaf blade to the root via nodes functioning as junctions, which were detected by X-ray computed tomography. These findings imply the diffusion of gas along the aerenchyma, which does not consume energy, has enabled plants to adapt to aquatic environments. Additionally, there were no major differences in [13 N]N2 gas movement between paddy rice and deepwater rice plants, indicative of a common aeration mechanism in the two varieties, despite the difference in their response to flooding.

Venous Sac and Feeding Artery Embolization versus Feeding Artery Embolization Alone for Treating Pulmonary Arteriovenous Malformations: Draining Vein Size Outcomes.

PURPOSE: To investigate and compare venous sac and feeding artery embolization (VFE) with feeding artery embolization (FAE) alone for treatment of pulmonary arteriovenous malformations (PAVMs), based on difference in outcomes in decrease of the size of the draining vein. MATERIALS AND METHODS: Twenty-six patients (7 male and 19 female; median age [interquartile range], 58 years [46-65 years]) with 42 simple PAVMs treated with coil embolization between August 2005 and December 2018 were retrospectively evaluated. Twenty PAVMs were treated with FAE early in the study period and compared with 22 PAVMs treated with VFE later in the study period. Follow-up computed tomography images obtained 8-20 months after embolotherapy were used for outcome analysis. Data related to patient demographics; follow-up period; baseline diameters of the feeding artery, venous sac, and draining vein; draining vein diameter after treatment; and decrease in the size of the draining vein, including the number reaching a threshold of 70% decrease, were compared between the 2 groups. RESULTS: The draining vein decreased in size by a median of 46.4% in the FAE group and 66.3% in the VFE group, and the difference between the 2 groups was statistically significant (P = .009). There were no significant differences in the other parameters. CONCLUSIONS: VFE leads to a greater decrease in the size of the draining vein than FAE, suggesting that VFE results in more complete occlusion than FAE for treatment of PAVMs.

Structural and functional characterization of nylon hydrolases.

Biodegradation of synthetic polymers is recognized as a useful way to reduce their environmental load and pollution, loss of natural resources, extensive energy consumption, and generation of greenhouse gases. The potential use of enzymes responsible for the degradation of the targeted polymers is an effective approach which enables the conversion of the used polymers to original monomers and/or other useful compounds. In addition, the enzymes are expected to be applicable in industrial processes such as improving the surface structures of the polymers. Especially, conversion of the solid polymers to soluble oligomers/monomers is a key step for the biodegradation of the polymers. Regarding the hydrolysis of polyamides, three enzymes, 6-aminohexanoate-cyclic-dimer hydrolase (NylA), 6-aminohexanoate-dimer hydrolase (NylB), and 6-aminohexanoate-oligomer endo-hydrolase (nylon hydrolase, NylC), are found in several bacterial strains. In this chapter, we describe our approach for the screening of microorganisms which degrade nylons and related compounds; preparation of substrates; assay of hydrolytic activity for soluble and insoluble substrates; and X-ray crystallographic and computational approaches for analysis of structure and catalytic mechanisms of the nylon-degrading enzymes.

Local Efficacy and Safety of Transarterial Chemoembolization for Hepatocellular Carcinoma: Epirubicin-Loaded DC Beads vs. Epirubicin-Lipiodol Emulsion with Gelatin Sponge (cTACE).

Purpose: To compare the efficacy and safety between epirubicin-loaded DC Beads (DCB-TACE) and conventional TACE (cTACE) used in transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). Materials and Methods: This retrospective study enrolled 64 patients (mean age, 73.3 years; 44 men, 20 women) who underwent initial DCB-TACE between 2014 and 2015, and 66 patients (mean age, 71.3 years; 38 men, 28 women) who underwent initial cTACE between 2011 and 2013 as historical controls. Treatment effects on the target lesions at 3 months after TACE, the period until re-treatment of the target lesion, and adverse events after TACE were compared between the groups. Univariate and multivariate analyses were also performed to estimate the factors influencing the treatment effects. Results: Based on the Response Evaluation Criteria in Cancer of the Liver version 2015, treatment response of the target lesions equivalent to a complete response and termed as TE4, was 51.0% (53/104) in the DCB-TACE group and 74.4% (64/86) in the cTACE group (p<0.001). Multivariate analysis revealed that the TACE procedure, Child-Pugh score, serum aspartate aminotransferase (AST) level, alpha fetoprotein level, and tumor size were independent significant predictors of TE4. The frequencies of elevated serum AST and alanine transaminase levels after TACE were significantly lower in patients in the DCB-TACE group (p<0.001 each). No significant difference in biliary/liver damage was evident between the groups. Conclusion: The local efficacy of cTACE was higher than that of DCB-TACE. Adverse events were milder after DCB-TACE than after cTACE.

Functional Domain Order of an Anti-EGFR × Anti-CD16 Bispecific Diabody Involving NK Cell Activation.

Bispecific antibodies (bsAbs) have emerged as promising therapeutics. A bispecific diabody (bsDb) is a small bsAb consisting of two distinct chimeric single-chain components, with two possible arrangements of the domains. We previously reported the effect of domain order on the function of a humanized bsDb targeting the epidermal growth factor receptor (EGFR) on cancer cells, and CD3 on T cells. Notably, the co-localization of a T-cell receptor (TCR) with CD3 is bulky, potentially affecting the cross-linking ability of bsDbs, due to steric hindrance. Here, we constructed and evaluated humanized bsDbs, with different domain orders, targeting EGFR and CD16 on natural killer (NK) cells (hEx16-Dbs). We predicted minimal effects due to steric hindrance, as CD16 lacks accessory molecules. Interestingly, one domain arrangement displayed superior cytotoxicity in growth inhibition assays, despite similar cross-linking abilities for both domain orders tested. In hEx16-Dbs specifically, domain order might affect the agonistic activity of the anti-CD16 portion, which was supported by a cytokine production test, and likely contributed to the superiority of one of the hEx16-Dbs. Our results indicate that both the target antigen and mode of action of an antibody must be considered in the construction of highly functional bsAbs.

Efficacy of prophylactic selective arterial embolization for renal angiomyolipomas: identifying predictors of 50% volume reduction.

BACKGROUND: Transcatheter arterial embolization (TAE) has been widely performed for renal angiomyolipomas (AMLs) as prophylaxis or emergency treatment. On the other hand, mammalian target of rapamycin (mTOR) inhibitors have recently been used for tuberous sclerosis (TSC)-related AMLs, and no comparison between the effectiveness of mTOR inhibitors versus prophylactic selective TAE has yet been performed. Therefore, the purpose of this study was to evaluate the efficacy of TAE for AML tumor volume reduction and predictors of tumor volume decrease over 50%, with reference to the EXIST-2 trial. METHODS: A total of 44 patients who underwent 48 prophylactic embolization procedures for 50 AMLs in a single institution between 2004 and 2018 were included. Indications for TAE of AMLs were tumor size ≥4 cm or aneurysm ≥5 mm in diameter on contrast-enhanced computed tomography (CECT). Microspheres, ethanol, and micro-coils were used as embolic agents. The percentage volume reduction from before TAE to the minimum volume during follow-up after TAE was calculated, and predictors for 50% volume reduction were identified by univariate and multivariate binary logistic regression analyses. RESULTS: The technical success rate was 100% (50 of 50). No severe acute complications related to the procedure were encountered. Tumor volume reduction of ≥50% was observed in 35/50 AMLs. There was a significant difference in the rate of tumor volume reduction of 50% between the presence and absence of an aneurysm ≥5 mm and between tumor diameter ≥ 70 mm and < 70 mm on univariate analysis. On multivariate analysis, tumor diameter < 70 mm was the only independent predictor of significant tumor volume reduction after TAE. CONCLUSION: Prophylactic selective TAE for AMLs has good tumor-reduction effects, especially for AMLs with tumor diameter < 70 mm.

Antagonistic regulation of the gibberellic acid response during stem growth in rice.

The size of plants is largely determined by growth of the stem. Stem elongation is stimulated by gibberellic acid1-3. Here we show that internode stem elongation in rice is regulated antagonistically by an 'accelerator' and a 'decelerator' in concert with gibberellic acid. Expression of a gene we name ACCELERATOR OF INTERNODE ELONGATION 1 (ACE1), which encodes a protein of unknown function, confers cells of the intercalary meristematic region with the competence for cell division, leading to internode elongation in the presence of gibberellic acid. By contrast, upregulation of DECELERATOR OF INTERNODE ELONGATION 1 (DEC1), which encodes a zinc-finger transcription factor, suppresses internode elongation, whereas downregulation of DEC1 allows internode elongation. We also show that the mechanism of internode elongation that is mediated by ACE1 and DEC1 is conserved in the Gramineae family. Furthermore, an analysis of genetic diversity suggests that mutations in ACE1 and DEC1 have historically contributed to the selection of shorter plants in domesticated populations of rice to increase their resistance to lodging, and of taller plants in wild species of rice for adaptation to growth in deep water. Our identification of these antagonistic regulatory factors enhances our understanding of the gibberellic acid response as an additional mechanism that regulates internode elongation and environmental fitness, beyond biosynthesis and gibberellic acid signal transduction.

Metabolite and Phytohormone Profiling Illustrates Metabolic Reprogramming as an Escape Strategy of Deepwater Rice during Partially Submerged Stress.

Rice varieties that can survive under submergence conditions respond to flooding either by enhancing internode elongation or by quiescence of shoot elongation. Despite extensive efforts to identify key metabolites triggered by complete submergence of rice possessing SUBMERGENCE 1 (SUB1) locus, metabolic responses of internode elongation of deepwater rice governed by the SNORKEL 1 and 2 genes remain elusive. This study investigated specific metabolomic responses under partial submergence (PS) to deepwater- (C9285) and non-deepwater rice cultivars (Taichung 65 (T65)). In addition, we examined the response in a near-isogenic line (NIL-12) that has a C9285 genomic fragment on chromosome 12 introgressed into the genetic background of T65. Under short-term submergence (0-24 h), metabolite profiles of C9285, NIL-12, and T65 were compared to extract significantly changed metabolites in deepwater rice under PS conditions. Comprehensive metabolite and phytohormone profiling revealed increases in metabolite levels in the glycolysis pathway in NIL-12 plants. Under long-term submergence (0-288 h), we found decreased amino acid levels. These metabolomic changes were opposite when compared to those in flood-tolerant rice with SUB1 locus. Auxin conjugate levels related to stress response decreased in NIL-12 lines relative to T65. Our analysis helped clarify the complex metabolic reprogramming in deepwater rice as an escape strategy.

The efficacy of uterine artery embolization with gelatin sponge for retained products of conception with bleeding and future pregnancy outcomes.

BACKGROUND: Retained products of conception (RPOC) with hemorrhage need intervention when RPOC persist and remain symptomatic. The safety and efficacy of uterine artery embolization (UAE) for RPOC using gelatin sponge (GS) alone, and fertility after UAE for RPOC remain unknown. The purpose of this study is to retrospectively investigate the efficacy of UAE for RPOC with bleeding and future pregnancy outcomes. METHODS: Between 2007 and 2016, 14 patients (mean age, 33 years old) diagnosed as RPOC with bleeding received UAE using GS at our institution. Pregnancy outcomes were vaginal delivery (n = 7), miscarriage (n = 4), and termination (n = 3). Four patients received dilation and curettage/evacuation (D&C/E) for treatment of RPOC before bleeding occurred. The mean time interval from the end of pregnancy to bleeding was 28 days. Technical success, clinical success, complications, angiographic features and fertility after UAE were retrospectively assessed. RESULTS: Technical success was achieved in 13 patients (93%) and clinical success was achieved in all 14 patients. No major complications occurred. The angiographic features of RPOC were tortuous feeders with flow into a focal blush of contrast (n = 14). Additional findings were pseudoaneurysm (n = 6), early venous return (n = 4), and extravasation (n = 2). Pseudoaneurysm was observed significantly more often in patients who received D&C/E before UAE compared to those who received conservative treatment alone (P = 0.015). The mean follow-up period was 29 months. Six patients achieved six pregnancies an average of 29 months after UAE. CONCLUSION: UAE using GS may be an effective and safe treatment for RPOC with hemorrhage that can preserve fertility.

Diel O2 Dynamics in Partially and Completely Submerged Deepwater Rice: Leaf Gas Films Enhance Internodal O2 Status, Influence Gene Expression and Accelerate Stem Elongation for 'Snorkelling' during Submergence.

Deepwater rice has a remarkable shoot elongation response to partial submergence. Shoot elongation to maintain air-contact enables 'snorkelling' of O2 to submerged organs. Previous research has focused on partial submergence of deepwater rice. We tested the hypothesis that leaf gas films enhance internode O2 status and stem elongation of deepwater rice when completely submerged. Diel patterns of O2 partial pressure (pO2) were measured in internodes of deepwater rice when partially or completely submerged, and with or without gas films on leaves, for the completely submerged plants. We also took measurements for paddy rice. Deepwater rice elongated during complete submergence and the shoot tops emerged. Leaf gas films improved O2 entry during the night, preventing anoxia in stems, which is of importance for elongation of the submerged shoots. Expressions of O2 deprivation inducible genes were upregulated in completely submerged plants during the night, and more so when gas films were removed from the leaves. Diel O2 dynamics showed similar patterns in paddy and deepwater rice. We demonstrated that shoot tops in air enabled 'snorkelling' and increased O2 in internodes of both rice ecotypes; however, 'snorkelling' was achieved only by rapid shoot elongation by deepwater rice, but not by paddy rice.