Germination of photoblastic lettuce seeds is regulated via the control of endogenous physiologically active gibberellin content, rather than of gibberellin responsiveness

Phytochrome regulates lettuce (Lactuca sativa L. cv. Grand Rapids) seed germination via the control of the endogenous level of bioactive gibberellin (GA). In addition to the previously identified LsGA20ox1, LsGA20ox2, LsGA3ox1, LsGA3ox2, LsGA2ox1, and LsGA2ox2, five cDNAs were isolated from lettuce seeds: LsCPS, LsKS, LsKO1, LsKO2, and LsKAO. Using an Escherichia coli expression system and functional assays, it is shown that LsCPS and LsKS encode ent-copalyl diphosphate synthase and ent-kaurene synthase, respectively. Using a Pichia pastoris system, it was found that LsKO1 and LsKO2 encode ent-kaurene oxidases and LsKAO encodes ent-kaurenoic acid oxidase. A comprehensive expression analysis of GA metabolism genes using the quantitative reverse transcription polymerase chain reaction suggested that transcripts of LsGA3ox1 and LsGA3ox2, both of which encode GA 3-oxidase for GA activation, were primarily expressed in the hypocotyl end of lettuce seeds, were expressed at much lower levels than the other genes tested, and were potently up-regulated by phytochrome. Furthermore, LsDELLA1 and LsDELLA2 cDNAs that encode DELLA proteins, which act as negative regulators in the GA signalling pathway, were isolated from lettuce seeds. The transcript levels of these two genes were little affected by light. Lettuce seeds in which de novo GA biosynthesis was suppressed responded almost identically to exogenously applied GA, irrespective of the light conditions, suggesting that GA responsiveness is not significantly affected by light in lettuce seeds. It is proposed that lettuce seed germination is regulated mainly via the control of the endogenous content of bioactive GA, rather than the control of GA responsiveness

The eCura system as a novel indicator for the necessity of salvage surgery after non-curative ESD for gastric cancer: A case-control study.

Endoscopic submucosal dissection (ESD) for early gastric cancer does not always lead to complete cancer resection. The aim of this study was to determine indicators for cancer residue (CR) status in cases of non-curative ESD. We analyzed 47 cases of non-curative ESD followed by salvage surgery and collected data regarding the rates of CR, which included both local CR and lymph node metastasis (LNM). To elucidate the risk factors for CR status, we compared the CR positive and the CR negative groups among surgical specimens according to the following variables obtained from ESD findings: tumor location, tumor size, depth of invasion, lympho-vascular invasion, histological margin, and histological diagnosis. The eCura system, which is an LNM risk scoring system, was also applied and scores were calculated in each case as follows: 3 points for lymphatic invasion and 1 point each for tumor size >30 mm, positive vertical margin, venous invasion, and submucosal invasion ≥500 μm. There were 9 (19%) CR positive cases, which included 6 cases of local CR and 4 cases of LNM; no cancer was detected in over 80% of the patients. The eCura scoring system was the only significant factor for CR status: the higher the eCura score, the greater the CR positivity (p = 0.0128). In particular, all patients in the low-risk group (score = 0-1 point) had no CR. Although no cancer recurrence was observed during a median follow-up of 4 years, 2 patients died of pneumonia. In conclusion, the eCura system might make it possible to select appropriate cases for salvage surgery

Accuracy of Preoperative Endoscopy in Determining Tumor Location Required for Surgical Planning for Esophagogastric Junction Cancer

Purpose: The surgical strategy for esophagogastric junction (EGJ) cancer depends on the tumor location as measured relative to the EGJ line. The purpose of this study was to clarify the accuracy of diagnostic endoscopy in different clinicopathological backgrounds. Methods: Subjects were 74 consecutive patients with abdominal esophagus to upper gastric cancer who underwent surgical resection. Image-enhanced endoscopy with narrow-band imaging (NBI) was used to determine the EGJ line, prioritizing the presence of palisade vessels, followed by the upper end of gastric folds, as a landmark. The relative positional relationship between the tumor epicenter and the EGJ line was classified into six categories, and the agreement between endoscopic and pathologic diagnoses was examined to evaluate prediction accuracy. Results: The concordance rate of 69 eligible cases was 87% with a kappa coefficient (K) of 0.81. The palisade vessels were observed in 62/69 patients (89.9%). Of the 37 pathological EGJ cancers centered within 2 cm above and below the EGJ line, Barrett’s esophagus was found to be a significant risk factor for discordance (risk ratio, 4.40; p = 0.042); the concordance rate of 60% (K = 0.50) in the Barrett’s esophagus group was lower than the rate of 91% (K = 0.84) in the non-Barrett’s esophagus group. In five of six discordant cases, the EGJ line was estimated to be proximal to the actual line. Conclusion: Diagnostic endoscopy is beneficial for estimating the location of EGJ cancer, with a risk of underestimating esophageal invasion length in patients with Barrett’s esophagus

Changes in the transcript levels of gibberellin (GA) metabolism genes in imbibed lettuce seeds after various light treatments

(A) Time-course of lettuce seed germination after light treatment. Zero (0) h indicates seeds imbibed for 3 h in the dark that received no light treatment. FR, FR/R, and FR/R/FR indicate seeds treated with far-red light, far-red followed by red light, and far-red followed by red and then far-red light, respectively. FR/R+ABA indicates seeds treated with far-red followed by red light and 0.1 mM ABA. Triplicate experiments were performed, and means with standard errors are shown. (B) Expression levels of GA metabolism genes after light treatment. The expression levels of these genes were analysed by QRT-PCR. The results were normalized to the expression of 18S rRNA (internal control); the expression levels of all genes examined are given relative to the reference value of the transcript level of at 0 h, set to 1. Three independent experiments were performed, and means with standard errors are shown.<p><b>Copyright information:</b></p><p>Taken from "Germination of photoblastic lettuce seeds is regulated via the control of endogenous physiologically active gibberellin content, rather than of gibberellin responsiveness"</p><p></p><p>Journal of Experimental Botany 2008;59(12):3383-3393.</p><p>Published online 24 Jul 2008</p><p>PMCID:PMC2529229.</p><p></p

Changes in the transcript levels of gibberellin (GA) metabolism genes in the cotyledon end and hypocotyl end of lettuce seeds

(A) Frozen seeds were divided into two parts: cotyledon end, including the cotyledons (Cot), fruit wall (FW), seed coat (SC), and endosperm (ES); and the hypocotyl end, including the hypocotyl (Hyp), root apical meristem (RAM), shoot apical meristem (SAM), and part of the Cot, FW, SC, and ES. (B) Expression levels of GA metabolism genes after light treatment, determined using QRT-PCR. See for light treatments. The results were normalized to the expression of 18S rRNA (internal control), and the highest value was set to 100. Two independent experiments were performed, and means with standard errors are shown.<p><b>Copyright information:</b></p><p>Taken from "Germination of photoblastic lettuce seeds is regulated via the control of endogenous physiologically active gibberellin content, rather than of gibberellin responsiveness"</p><p></p><p>Journal of Experimental Botany 2008;59(12):3383-3393.</p><p>Published online 24 Jul 2008</p><p>PMCID:PMC2529229.</p><p></p

Effects of abscisic acid (ABA) treatment on the expression levels of gibberellin (GA) metabolism genes in imbibed lettuce seeds

(A) The expression levels of the genes were analysed by QRT-PCR. The results were normalized to the expression of 18S rRNA (internal control), and the expression levels of all genes examined are given relative to the reference value of the transcript level of at 0 h, set to 1. Three independent experiments were performed, and means with standard errors are shown. (B) Expression analysis using seeds that had been cut in half. The results were normalized to the expression of 18S rRNA (internal control), and the highest value was set to 100. Two independent experiments were performed, and means with standard errors are shown.<p><b>Copyright information:</b></p><p>Taken from "Germination of photoblastic lettuce seeds is regulated via the control of endogenous physiologically active gibberellin content, rather than of gibberellin responsiveness"</p><p></p><p>Journal of Experimental Botany 2008;59(12):3383-3393.</p><p>Published online 24 Jul 2008</p><p>PMCID:PMC2529229.</p><p></p