Analysis of Drought Tolerance and Associated Traits in Upland Cotton at the Seedling Stage.

(1) Background: Upland cotton (Gossypium hirsutum L.) is the most important natural fiber worldwide, and it is extensively planted and plentifully used in the textile industry. Major cotton planting regions are frequently affected by abiotic stress, especially drought stress. Drought resistance is a complex, quantitative trait. A genome-wide association study (GWAS) constitutes an efficient method for dissecting the genetic architecture of complex traits. In this study, the drought resistance of a population of 316 upland cotton accessions was studied via GWAS. (2) Methods: GWAS methodology was employed to identify relationships between molecular markers or candidate genes and phenotypes of interest. (3) Results: A total of 8, 3, and 6 SNPs were associated with the euphylla wilting score (EWS), cotyledon wilting score (CWS), and leaf temperature (LT), respectively, based on a general linear model and a factored spectrally transformed linear mixed model. For these traits, 7 QTLs were found, of which 2 each were located on chromosomes A05, A11, and D03, and of which 1 was located on chromosome A01. Importantly, in the candidate regions WRKY70, GhCIPK6, SnRK2.6, and NET1A, which are involved in the response to abscisic acid (ABA), the mitogen-activated protein kinase (MAPK) signaling pathway and the calcium transduction pathway were identified in upland cotton at the seedling stage under drought stress according to annotation information and linkage disequilibrium (LD) block analysis. Moreover, RNA sequencing analysis showed that WRKY70, GhCIPK6, SnRK2.6, and NET1A were induced by drought stress, and the expression of these genes was significantly different between normal and drought stress conditions. (4) Conclusions: The present study should provide some genomic resources for drought resistance in upland cotton. Moreover, the germplasm of the different phenotypes, the detected SNPs and, the potential candidate genes will be helpful for molecular marker-assisted breeding studies about increased drought resistance in upland cotton.

[Low dose all-trans retinoic acid and androgen therapy for patients with myelodysplastic syndrome].

To explore therapeutic efficacy of androgens and low dose all-trans retinoic acid (ATRA) for myelodysplastic syndrome (MDS) patients, 55 patients of MDS were observed, including 41 cases of refractory anemia (RA), 11 cases of refractory anemia with excess of blasts (RAEB), 2 cases of refractory anemia with excess of blasts in transformation (RAEB-t) and 1 case of chronic myeloic-monocytic leukemia (CMML). These patients received danazol (600 mg/day) or stanazol (6 mg/day) and ATRA (10 mg/day) for at least 3 months. The results showed that according to MDS international working group response criteria, at the end of three months,complete remission (CR) was seen in 1 patient, partial remission (PR) was found in 2 patients. Hematologic improvement: major response (MaR) were seen in 15 patients, minor response (MiR) were seen in 4 patients. The total response rate was 35.8%. In conclusion, danazol or stanazol in combination with low dose ATRA are partialy effective in therapy for patients with low-risk myelodysplastic syndrome.