The aim of this study was to investigate the physiological basis and molecular mechanism of genotypic variation in drought response of maize seedlings. Comparative physiological and proteomic analyses were conducted in the leaves of droughttolerant Liyu 35 (LY) and drought-sensitive Denghai 605 (DH) maize genotype seedlings. Drought induced a significant decrease of relative water content and osmotic potential of leaves, length and volume of roots, and total dry weight, but significantly increased malondialdehyde in DH seedlings. However, root dry weight , proline content and antioxidant enzyme activities increased more in LY than in DH. Forty-two spots in LY and 17 spots in DH that showed significant abundance variations were identified by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry. These drought-responsive proteins were mainly involved in biological processes of photosynthesis, defense and oxidative stress, carbohydrate and energy metabolism, protein synthesis and processing, and cell wall biogenesis and degradation. Among them, proteins involved in defense and oxidative stress, and protein synthesis and processing were largely enriched in the LY genotype, which may contribute to a natural variation of drought resistance between LY and DH genotypes. The altered protein abundance and corresponding physiological-biochemical response shed some light on molecular mechanisms related to drought tolerance in drought-tolerant maize and provide key candidate proteins for genetic improvement of maize.

ABSTRACT. Previous studies investigating the association between corneodesmosin (CDSN) polymorphisms and psoriasis risk have provided inconsistent results. The aim of our study was to clarify the effects of CDSN -619C/T polymorphism on psoriasis risk by conducting a meta-analysis. We conducted searches of the published literature in Pubmed and Embase databases up to October 2010. Six studies with a total of 842 psoriasis cases and 981 healthy controls were retrieved. Statistical analysis was performed with the programs Review Manager (version 5.0.24) and Stata (version 9.2). Metaanalysis results showed that there was no significant difference in CDSN -619C/T genotype distribution between psoriasis and control in the comparisons of C allele vs T allele, CC vs CT + TT, CC + CT vs TT, CC vs TT, and CC vs CT (respectively: OR = 1.28, 95%CI = 0.82-2.00, P = 0.28; OR = 1.33, 95%CI = 0.80-2.21, P = 0.28; OR = 1.23, 95%CI = 0.80-1.91, P = 0.35; OR = 1.41, 95%CI = 0.64-3.12, P = 0.40; OR = 1.30, 95%CI = 0.81-2.06, P = 0.27). In the subgroup analysis by ethnicity, results also showed no significant association between ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 10 (4): 3632-3640 (2011) CDSN -619C/T polymorphism and psoriasis risk 3633CDSN -619C/T polymorphism and susceptibility to psoriasis in both Caucasian and Asian populations. In conclusion, this meta-analysis suggests that CDSN -619C/T polymorphism may not be associated with susceptibility to psoriasis.