Lenvatinib Plus Pembrolizumab Versus Sunitinib in First-Line Treatment of Advanced Renal Cell Carcinoma: Final Prespecified Overall Survival Analysis of CLEAR, a Phase III Study.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We present the final prespecified overall survival (OS) analysis of the open-label, phase III CLEAR study in treatment-naïve patients with advanced renal cell carcinoma (aRCC). With an additional follow-up of 23 months from the primary analysis, we report results from the lenvatinib plus pembrolizumab versus sunitinib comparison of CLEAR. Treatment-naïve patients with aRCC were randomly assigned to receive lenvatinib (20 mg orally once daily in 21-day cycles) plus pembrolizumab (200 mg intravenously once every 3 weeks) or sunitinib (50 mg orally once daily [4 weeks on/2 weeks off]). At this data cutoff date (July 31, 2022), the OS hazard ratio (HR) was 0.79 (95% CI, 0.63 to 0.99). The median OS (95% CI) was 53.7 months (95% CI, 48.7 to not estimable [NE]) with lenvatinib plus pembrolizumab versus 54.3 months (95% CI, 40.9 to NE) with sunitinib; 36-month OS rates (95% CI) were 66.4% (95% CI, 61.1 to 71.2) and 60.2% (95% CI, 54.6 to 65.2), respectively. The median progression-free survival (95% CI) was 23.9 months (95% CI, 20.8 to 27.7) with lenvatinib plus pembrolizumab and 9.2 months (95% CI, 6.0 to 11.0) with sunitinib (HR, 0.47 [95% CI, 0.38 to 0.57]). Objective response rate also favored the combination over sunitinib (71.3% v 36.7%; relative risk 1.94 [95% CI, 1.67 to 2.26]). Treatment-emergent adverse events occurred in >90% of patients who received either treatment. In conclusion, lenvatinib plus pembrolizumab achieved consistent, durable benefit with a manageable safety profile in treatment-naïve patients with aRCC.

Phase 3 CLEAR study in patients with advanced renal cell carcinoma: outcomes in subgroups for the lenvatinib-plus-pembrolizumab and sunitinib arms.

Introduction: The phase 3 CLEAR study demonstrated that lenvatinib plus pembrolizumab significantly improved efficacy versus sunitinib as first-line treatment for patients with advanced renal cell carcinoma (RCC). Prognostic features including presence and/or site of baseline metastases, prior nephrectomy, and sarcomatoid features have been associated with disease and treatment success. This subsequent analysis explores outcomes in patients with or without specific prognostic features. Methods: In CLEAR, patients with clear cell RCC were randomly assigned (1:1:1) to receive either lenvatinib (20 mg/day) plus pembrolizumab (200 mg every 3 weeks), lenvatinib (18 mg/day) plus everolimus (5 mg/day), or sunitinib alone (50 mg/day, 4 weeks on, 2 weeks off). In this report, progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) were all assessed in the lenvatinib-plus-pembrolizumab and the sunitinib arms, based on baseline features: lung metastases, bone metastases, liver metastases, prior nephrectomy, and sarcomatoid histology. Results: In all the assessed subgroups, median PFS was longer with lenvatinib-plus-pembrolizumab than with sunitinib treatment, notably among patients with baseline bone metastases (HR 0.33, 95% CI 0.21-0.52) and patients with sarcomatoid features (HR 0.39, 95% CI 0.18-0.84). Median OS favored lenvatinib plus pembrolizumab over sunitinib irrespective of metastatic lesions at baseline, prior nephrectomy, and sarcomatoid features. Of interest, among patients with baseline bone metastases the HR for survival was 0.50 (95% CI 0.30-0.83) and among patients with sarcomatoid features the HR for survival was 0.91 (95% CI 0.32-2.58); though for many groups, median OS was not reached. ORR also favored lenvatinib plus pembrolizumab over sunitinib across all subgroups; similarly, complete responses also followed this pattern. Conclusion: Efficacy outcomes improved following treatment with lenvatinib-plus-pembrolizumab versus sunitinib in patients with RCC-irrespective of the presence or absence of baseline lung metastases, baseline bone metastases, baseline liver metastases, prior nephrectomy, or sarcomatoid features. These findings corroborate those of the primary CLEAR study analysis in the overall population and support lenvatinib plus pembrolizumab as a standard of care in 1L treatment for patients with advanced RCC. Clinical trial registration: ClinicalTrials.gov, identifier NCT02811861.

Efficacy and safety of lenvatinib plus pembrolizumab vs sunitinib in the East Asian subset of patients with advanced renal cell carcinoma from the CLEAR trial.

In the CLEAR trial, lenvatinib plus pembrolizumab met study endpoints of superiority vs sunitinib in the first-line treatment of patients with advanced renal cell carcinoma. We report the efficacy and safety results of the East Asian subset (ie, patients in Japan and the Republic of Korea) from the CLEAR trial. Of 1069 patients randomly assigned to receive either lenvatinib plus pembrolizumab, lenvatinib plus everolimus or sunitinib, 213 (20.0%) were from East Asia. Baseline characteristics of patients in the East Asian subset were generally comparable with those of the global trial population. In the East Asian subset, progression-free survival was considerably longer with lenvatinib plus pembrolizumab vs sunitinib (median 22.1 vs 11.1 months; HR 0.38; 95% CI: 0.23-0.62). The HR for overall survival comparing lenvatinib plus pembrolizumab vs sunitinib was 0.71; 95% CI: 0.30-1.71. The objective response rate was higher with lenvatinib plus pembrolizumab vs sunitinib (65.3% vs 49.2%; odds ratio 2.14; 95% CI: 1.07-4.28). Dose reductions due to treatment-emergent adverse events (TEAEs) commonly associated with tyrosine kinase inhibitors occurred more frequently than in the global population. Hand-foot syndrome was the most frequent any-grade TEAE with lenvatinib plus pembrolizumab (66.7%) and sunitinib (57.8%), a higher incidence compared to the global population (28.7% and 37.4%, respectively). The most common grade 3 to 5 TEAEs were hypertension with lenvatinib plus pembrolizumab (20%) and decreased platelet count with sunitinib (21.9%). Efficacy and safety for patients in the East Asian subset were generally similar to those of the global population, except as noted.

Corrigendum: Phase 3 CLEAR study in patients with advanced renal cell carcinoma: outcomes in subgroups for the lenvatinib-plus-pembrolizumab and sunitinib arms.

[This corrects the article DOI: 10.3389/fonc.2023.1223282.].

Health-related quality-of-life outcomes in patients with advanced renal cell carcinoma treated with lenvatinib plus pembrolizumab or everolimus versus sunitinib (CLEAR): a randomised, phase 3 study.

BACKGROUND: Results from the phase 3 CLEAR study showed that lenvatinib plus pembrolizumab improved progression-free survival and overall survival compared with sunitinib in patients with advanced renal cell carcinoma. We aimed to assess the health-related quality-of-life (HRQOL) outcomes from the CLEAR study. METHODS: This open-label, randomised, phase 3 study was done across 200 hospitals and cancer centres in 20 countries. Patients were required to be 18 years or older, with advanced clear-cell renal cell carcinoma, and a Karnofsky performance status of 70% or higher. Patients who had received previous systemic anticancer therapy for renal cell carcinoma were not eligible. Patients were randomly assigned (1:1:1) to lenvatinib (oral 20 mg per day) plus pembrolizumab (intravenous 200 mg every 21 days), lenvatinib (oral 18 mg per day) plus everolimus (oral 5 mg per day) in 21-day cycles, or sunitinib (oral 50 mg per day, 4 weeks on followed by 2 weeks off). Patients were assigned to treatments with a computer-generated randomisation scheme and were stratified by geographical region and Memorial Sloan Kettering Cancer Center prognostic groups. The primary endpoint, previously reported, was progression-free survival, and HRQOL was a secondary endpoint. Most HRQOL analyses were done in patients who underwent randomisation, received at least one dose of study treatment, and had any HRQOL data. Completion and compliance analyses were done in the full analysis set. Functional Assessment of Cancer Therapy Kidney Symptom Index-Disease-Related Symptoms (FKSI-DRS), European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), and the EQ-5D-3 Level (EQ-5D-3L) preference questionnaire were administered at baseline and on day 1 of each subsequent 21-day cycle. This study is registered with ClinicalTrials.gov, NCT02811861, and is closed to new participants. FINDINGS: Between Oct 13, 2016, and July 24, 2019, 355 patients were randomly assigned to the lenvatinib plus pembrolizumab group, 357 to the lenvatinib plus everolimus group, and 357 to the sunitinib group. Median follow-up for HRQOL analyses was 12·9 months (IQR 5·6-22·3). Because of the promising efficacy and safety results of lenvatinib plus pembrolizumab in the first-line setting, we focus the HRQOL results in this report on that combination versus sunitinib. Mean change from baseline in the lenvatinib plus pembrolizumab group compared with the sunitinib group was -1·75 (SE 0·59) versus -2·19 (0·66) for FKSI-DRS, -5·93 (0·86) versus -6·73 (0·94) for EORTC QLQ-C30 global health status/quality of life (GHS/QOL), and -4·96 (0·85) versus -6·64 (0·94) for the EQ-5D visual analogue scale (VAS). Median time to first deterioration in the lenvatinib plus pembrolizumab group compared with the sunitinib group was 9·14 weeks (95% CI 6·43-12·14) versus 12·14 weeks (9·14-15·29; HR 1·13 [95% CI 0·94-1·35], log-rank p=0·20) for FKSI-DRS, 12·00 weeks (7·29-15·14) versus 9·14 weeks (6·29-12·14; 0·88 [0·74-1·05], log-rank p=0·17) for EORTC QLQ-C30 GHS/QOL, and 9·43 weeks (6·43-12·29) versus 9·14 weeks (6·29-12·00; 0·83 [0·70-0·99], log-rank p=0·041) for the EQ-5D VAS. Median time to definitive deterioration in the lenvatinib plus pembrolizumab group compared with the sunitinib group was 134·14 weeks (95% CI 120·00-not estimable) versus 117·43 weeks (90·14-131·29; HR 0·70 [95% CI 0·53-0·92], log-rank p=0·0081) for FKSI-DRS, 114·29 weeks (102·14-153·29) versus 75·14 weeks (57·29-105·14; 0·60 [0·47-0·77], log-rank p<0·0001) for EORTC QLQ-C30 GHS/QOL, and 124·86 weeks (94·71-134·57) versus 74·86 weeks (54·14-96·00; 0·67 [0·53-0·85], log-rank p=0·0012) for the EQ-5D VAS. No outcomes on any of the instruments significantly favoured sunitinib over lenvatinib plus pembrolizumab. Most HRQOL comparisons of lenvatinib plus everolimus versus sunitinib were similar or favoured sunitinib. INTERPRETATION: These HRQOL results demonstrate that patients given lenvatinib plus pembrolizumab treatment had similar or favourable scores compared with patients given sunitinib, particularly with respect to time to definitive deterioration. These results support the efficacy and safety profile of lenvatinib plus pembrolizumab as first-line therapy for patients with advanced renal cell carcinoma. FUNDING: Eisai (Nutley, NJ, USA) and Merck Sharp & Dohme, a subsidiary of Merck & Co (Kenilworth, NJ, USA).

Lenvatinib with etoposide plus ifosfamide in patients with refractory or relapsed osteosarcoma (ITCC-050): a multicentre, open-label, multicohort, phase 1/2 study.

BACKGROUND: Tyrosine kinase inhibitors have shown activity in osteosarcoma and might enhance the efficacy of chemotherapy. We aimed to determine the recommended phase 2 dose and antitumour activity of lenvatinib with etoposide plus ifosfamide in patients with refractory or relapsed osteosarcoma. METHODS: This multicentre, open-label, multicohort, phase 1/2 trial was done at 17 hospitals in six countries. Eligible patients were aged 2-25 years, had relapsed or refractory osteosarcoma, measurable or evaluable disease per Response Evaluation Criteria in Solid Tumors version 1.1, Lansky play-performance score or Karnofsky performance score of 50% or higher, up to one previous VEGF or VEGF receptor-targeted therapy, and a life expectancy of at least 3 months. This study includes a combination dose-finding phase 1 part (cohort 3A) and a phase 2 combination expansion in patients with osteosarcoma (cohort 3B). Lenvatinib was administered orally at a starting dose of 11 mg/m2 per day, capped at 24 mg per day, and etoposide (100 mg/m2 per day) plus ifosfamide (3000 mg/m2 per day) were administered intravenously on days 1-3 of each 21-day cycle for a maximum of five cycles. Lenvatinib monotherapy continued after these five cycles until disease progression, toxic effects, or patient choice to discontinue. The phase 1 primary endpoint was to determine the recommended phase 2 dose by evaluating dose-limiting toxicity and the phase 2 primary endpoint was progression-free survival at 4 months. Progression-free survival was measured in the full analysis set, which included all patients enrolled for efficacy outcomes; safety was assessed in all patients who received any study drug. This study is registered with ClinicalTrials.gov, NCT02432274. FINDINGS: 30 patients were screened for enrolment into cohort 3A between May 9, 2016, and June 3, 2019, and 22 patients for enrolment into cohort 3B between Sept 13, 2018, and July 18, 2019. Eight patients from cohort 3A and two from cohort 3B were ineligible for enrolment in the study. In phase 1, dose-limiting toxicities were observed in three patients (one in the lenvatinib 11 mg/m2 combination group and two in the 14 mg/m2 combination group) and the recommended phase 2 dose was determined as lenvatinib 14 mg/m2 per day (with daily dose cap of 24 mg) and etoposide 100 mg/m2 per day plus ifosfamide 3000 mg/m2 per day administered intravenously on days 1-3 of each 21-day cycle for a maximum of five cycles. 35 patients from phase 1 (cohort 3A; n=15) and phase 2 (cohort 3B; n=20) were treated at the recommended phase 2 dose and their results were pooled. Progression-free survival at 4 months was 51% (95% CI 34-69) in 18 of 35 patients per the binomial estimate. The most common grade 3-4 treatment-emergent adverse events were neutropenia (27 [77%] of 35), thrombocytopenia (25 [71%]), anaemia (19 [54%]), and decreased white blood cell count (19 [54%]). 26 [74%] of 35 patients had serious treatment-emergent adverse events and no treatment-related deaths occurred. INTERPRETATION: Lenvatinib with etoposide plus ifosfamide shows promising antitumour activity with no new safety signals in patients with refractory and relapsed osteosarcoma. These findings warrant further investigation in an ongoing randomised phase 2 study (NCT04154189). FUNDING: Eisai and Merck Sharp & Dohme.

An Open-Label Phase 1 Study to Determine the Effect of Lenvatinib on the Pharmacokinetics of Midazolam, a CYP3A4 Substrate, in Patients with Advanced Solid Tumors.

BACKGROUND AND OBJECTIVE: Lenvatinib is a multikinase inhibitor that inhibits enzyme activity but induces gene expression of cytochrome P450 3A4 (CYP3A4), an important enzyme for drug metabolism. We evaluated the impact of lenvatinib on CYP3A4 using midazolam as a probe substrate in patients with advanced solid tumors. The primary objective was to determine the pharmacokinetic effects of lenvatinib on midazolam, and the secondary objective was to assess the safety of lenvatinib. METHODS: This multicenter, open-label, nonrandomized, phase 1 study involved patients with advanced cancer that progressed after treatment with approved therapies or for which no standard therapies were available. RESULTS: Compared with baseline, coadministration of lenvatinib decreased the geometric mean ratio of the area under the concentration-time curve for midazolam on day 1 to 0.914 (90% confidence interval [CI] 0.850-0.983) but increased it on day 14 to 1.148 (90% CI 0.938-1.404). Coadministration of lenvatinib also decreased the geometric mean ratio of the maximum observed concentration for midazolam on day 1 to 0.862 (90% CI 0.753-0.988) but increased it on day 14 to 1.027 (90% CI 0.852-1.238). There was little change in the terminal elimination phase half-life of midazolam when administered with lenvatinib. The most common treatment-related adverse events were hypertension (20.0%), fatigue (16.7%), and diarrhea (10.0%). CONCLUSIONS: Coadministration of lenvatinib had no clinically relevant effect on the pharmacokinetics of midazolam, a CYP3A4 substrate. The adverse events were consistent with the known safety profile of lenvatinib, and no new safety concerns were identified. CLINICALTRIALS. GOV IDENTIFIER: NCT02686164.

Lenvatinib plus everolimus or pembrolizumab versus sunitinib in advanced renal cell carcinoma: study design and rationale.

AIM: Lenvatinib plus everolimus is approved for the treatment of advanced renal cell carcinoma (RCC) after one prior vascular endothelial growth factor-targeted therapy. Lenvatinib plus pembrolizumab demonstrated promising antitumor activity in a Phase I/II trial of RCC. METHODS: We describe the rationale and design of the CLEAR study, a three-arm Phase III trial comparing lenvatinib plus everolimus and lenvatinib plus pembrolizumab versus sunitinib monotherapy for first-line treatment of RCC. Eligible patients must have advanced clear cell RCC and must not have received any prior systemic anticancer therapy. The primary end point is progression-free survival; secondary end points include objective response rate, overall survival, safety, health-related quality of life and pharmacokinetics. Biomarker evaluations are included as exploratory end points.

Sarcoidosis and Sjögren's syndrome: clinical and salivary evaluation.

BACKGROUND: Sarcoidosis and Sjögren's syndrome are two different diseases; however, when affecting the salivary glands, both diseases exhibit similar clinical signs and symptoms, which often complicates the diagnosis. The purpose of this study was to investigate the possibility of using salivary electrophoresis to differentiate between the two diseases. METHODS: Saliva was collected from patients with sarcoidosis and patients with Sjögren's syndrome. Salivary flow rate, total protein, and electrophoretic profiles were examined. RESULTS: Mean salivary flow rate was 0.41 ± 0.07 ml/min/gland vs. 0.43 ± 0.07 ml/min/gland; total salivary protein was 130.0 ± 29.2 mg% vs. 104.0 ± 8.8 mg% for sarcoidosis vs. Sjögren's syndrome, respectively. No differences were observed in salivary flow rate, total salivary protein, or electrophoretic profile between patients with sarcoidosis and patients with Sjögren's syndrome (P = 0.768, 0.718, and 1.000, respectively). CONCLUSIONS: Salivary protein electrophoresis does not appear to be useful to differentiate between sarcoidosis and Sjögren's syndrome.

Oxalic acid biosynthesis is encoded by an operon in Burkholderia glumae.

Although the biosynthesis of oxalic acid is known to occur in a number of bacteria, the mechanism(s) regulating its production remains largely unknown. To date, there is no report on the identification of an oxalic acid biosynthetic pathway gene from bacteria. In an attempt to identify such a gene(s), a mutant screen was conducted using the simple oxalic acid-producing phytopathogenic bacterium, Burkholderia glumae. Four mutants that failed to produce oxalic acid were isolated from a transposon-mutagenized B. glumae library and named Burkholderia oxalate defective (Bod)1. DNA sequence analysis revealed that each mutant contained an insertion event at different sites in the same ORF, which we referred to as the oxalate biosynthetic component (obc)A locus. Complementation of the Bod1 mutant with the obcA gene, however, resulted only in a partial restoration of the oxalic acid-producing phenotype. Further complementation studies utilizing a larger DNA fragment encompassing the obcA locus coupled with deletion mutagenesis led to the identification of another ORF that we named the obcB locus, which was essential for higher levels of oxalic acid production. Transcript analysis indicated that both obcA and obcB are coexpressed and encoded on a single polycistron message.

The chloroplast protease subunit ClpP4 is a substrate of the E3 ligase AtCHIP and plays an important role in chloroplast function.

Animal CHIP proteins are chaperone-dependent E3 ubiquitin ligases that physically interact with Hsp70, Hsp90 and proteasome, promoting degradation of a selective group of non-native or damaged proteins in animal cells. The plant CHIP-like protein, AtCHIP, also plays important roles in protein turnover metabolism. AtCHIP interacts with a proteolytic subunit, ClpP4, of the chloroplast Clp protease in vivo, and ubiquitylates ClpP4 in vitro. The steady-state level of ClpP4 is reduced in AtCHIP-overexpressing plants under high-intensity light conditions, suggesting that AtCHIP targets ClpP4 for degradation and thereby regulates the Clp proteolytic activity in chloroplasts under certain stress conditions. Overexpression of ClpP4 in Arabidopsis leads to chlorotic phenotypes in transgenic plants, and chloroplast structures in the chlorotic tissues of ClpP4-overexpressing plants are abnormal and largely devoid of thylakoid membranes, suggesting that ClpP4 plays a critical role in chloroplast structure and function. As AtCHIP is a cytosolic protein that has been shown to play an important role in regulating an essential chloroplast protease, this research provides new insights into the regulatory networks controlling protein turnover catabolism in chloroplasts.

AtCHIP functions as an E3 ubiquitin ligase of protein phosphatase 2A subunits and alters plant response to abscisic acid treatment.

CHIP proteins are E3 ubiquitin ligases that promote degradation of Hsp70 and Hsp90 substrate proteins through the 26S proteasome in animal systems. A CHIP-like protein in Arabidopsis, AtCHIP, also has E3 ubiquitin ligase activity and has important roles to play under conditions of abiotic stress. In an effort to study the mode of action of AtCHIP in plant cells, proteins that physically interact with it were identified. Like its animal orthologs, AtCHIP interacts with a unique class of ubiquitin-conjugating enzymes (UBC or E2) that belongs to the stress-inducible UBC4/5 class in yeast. AtCHIP also interacts with other proteins, including an A subunit of protein phosphatase 2A (PP2A). This PP2A subunit appears to be a substrate of AtCHIP, because it can be ubiquitylated by AtCHIP in vitro and because the activity of PP2A is increased in AtCHIP-overexpressing plants in the dark or under low-temperature conditions. Unlike the rcn1 mutant, that has reduced PP2A activity due to a mutation in one of the A subunit genes of PP2A, AtCHIP-overexpressing plants are more sensitive to ABA treatment. Since PP2A was previously shown to be involved in low-temperature responses in plants, the low-temperature-sensitive phenotype observed in AtCHIP-overexpressing plants might be partly due to the change in PP2A activity. These data suggest that the E3 ubiquitin ligase AtCHIP may function upstream of PP2A in stress-responsive signal transduction pathways under conditions of low temperature or in the dark.

Expression of an Arabidopsis vacuolar sodium/proton antiporter gene in cotton improves photosynthetic performance under salt conditions and increases fiber yield in the field.

Drought and salinity are two major limiting factors in crop productivity. One way to reduce crop loss caused by drought and salinity is to increase the solute concentration in the vacuoles of plant cells. The accumulation of sodium ions inside the vacuoles provides a 2-fold advantage: (i) reducing the toxic levels of sodium in cytosol; and (ii) increasing the vacuolar osmotic potential with the concomitant generation of a more negative water potential that favors water uptake by the cell and better tissue water retention under high soil salinity. The success of this approach was demonstrated in several plants, where the overexpression of the Arabidopsis gene AtNHX1 that encodes a vacuolar sodium/proton antiporter resulted in higher plant salt tolerance. Overexpression of AtNHX1 increases sodium uptake in vacuoles, which leads to increased vacuolar solute concentration and therefore higher salt tolerance in transgenic plants. In an effort to engineer cotton for higher drought and salt tolerance, we created transgenic cotton plants expressing AtNHX1. These AtNHX1-expressing cotton plants generated more biomass and produced more fibers when grown in the presence of 200 mM NaCl in greenhouse conditions. The increased fiber yield was probably due to better photosynthetic performance and higher nitrogen assimilation rates observed in the AtNHX1-expressing cotton plants as compared with wild-type cotton plants under saline conditions. Furthermore, the field-grown AtNHX1-expressing cotton plants produced more fibers with better quality, indicating that AtNHX1 can indeed be used for improving salt stress tolerance in cotton.

Overexpression of the Arabidopsis 14-3-3 protein GF14 lambda in cotton leads to a "stay-green" phenotype and improves stress tolerance under moderate drought conditions.

The Arabidopsis gene GF14 lambda that encodes a 14-3-3 protein was introduced into cotton plants to explore the physiological roles that GF14 lambda might play in plants. The expression level of GF14 lambda under the control of the cauliflower mosaic virus 35S promoter varied in transgenic cotton plants, and lines that expressed GF14 lambda demonstrated a "stay-green" phenotype and improved water-stress tolerance. These lines wilted less and maintained higher photosynthesis than segregated non-transgenic control plants under water-deficit conditions. Stomatal conductance appears to be the major factor for the observed higher photosynthetic rates under water-deficit conditions. The stomatal aperture of transgenic plants might be regulated by GF14 lambda through some transporters such as H(+)-ATPase whose activities are controlled by their interaction with 14-3-3 proteins. However, since 14-3-3 proteins interact with numerous proteins in plant cells, many metabolic processes could be affected by the GF14 lambda overexpression. Whatever the mechanisms, the traits observed in the GF14 lambda-expressing cotton plants are beneficial to crops under certain water-deficit conditions.

Analysis of digenic epistatic effects and QE interaction effects QTL controlling grain weight in rice.

Immortalized F(2) population of rice (Oryza sativa L.) was developed by randomly mating F(1) among recombinant inbred (RI) lines derived from (Zhenshan 97B x Minghui 63), which allowed replications within and across environments. QTL (quantitative trait loci) mapping analysis on kilo-grain weight of immortalized F(2) population was performed by using newly developed software for QTL mapping, QTLMapper 2.0. Eleven distinctly digenic epistatic loci included a total of 15 QTL were located on eight chromosomes. QTL main effects of additive, dominance, and additive x additive, additive x dominance, and dominance x dominance interactions were estimated. Interaction effects between QTL main effects and environments (QE) were predicted. Less than 40% of single effects, most of which were additive effects, for identified QTL were significant at 5% level. The directional difference for QTL main effects suggested that these QTL were distributed in parents in the repulsion phase. This should make it feasible to improve kilo-grain weight of both parents by selecting appropriate new recombinants. Only few of the QE interaction effects were significant. Application prospect for QTL mapping achievements in genetic breeding was discussed.