Isolation and characterization of a catalase gene "HuCAT3" from pitaya (Hylocereus undatus) and its expression under abiotic stress.
Abiotic stresses usually cause H2O2 accumulation, with harmful effects, in plants. Catalase may play a key protective role in plant cells by detoxifying this excess H2O2. Pitaya (Hylocereus undatus) shows broad ecological adaptation due to its high tolerance to abiotic stresses, e.g. drought, heat and poor soil. However, involvement of the pitaya catalase gene (HuCAT) in tolerance to abiotic stresses is unknown. In the present study, a full-length HuCAT3 cDNA (1870 bp) was isolated from pitaya based on our previous microarray data and RACE method. The cDNA sequence and deduced amino acid sequence shared 73-77% and 75-80% identity with other plant catalases, respectively. HuCAT3 contains conserved catalase family domain and catalytic sites. Pairwise comparison and phylogenetic analysis indicated that HuCAT3 is most similar to Eriobotrya japonica CAT, followed by Dimocarpus longan CAT and Nicotiana tabacum CAT1. Expression profile analysis demonstrated that HuCAT3 is mainly expressed in green cotyledons and mature stems, and was regulated by H2O2, drought, cold and salt stress, whereas, its expression patterns and maximum expression levels varied with stress types. HuCAT activity increased as exposure to the tested stresses, and the fluctuation of HuCAT activity was consistent with HuCAT3 mRNA abundance (except for 0.5 days upon drought stress). HuCAT3 mRNA elevations and HuCAT activities changes under cold stress were also in conformity with the cold tolerances among the four genotypes. The obtained results confirmed a major role of HuCAT3 in abiotic stress response of pitaya. This may prove useful in understanding pitaya's high tolerance to abiotic stresses at molecular level.
Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Guizhou University), Ministry of Education, Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, Guizhou Province, PR China; College of Agriculture, Guizhou University, Guiyang 550025, Guizhou Province, PR China.
Qiong
Q
Nie
Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Guizhou University), Ministry of Education, Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, Guizhou Province, PR China.
Guo-Li
GL
Gao
Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Guizhou University), Ministry of Education, Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, Guizhou Province, PR China.
Qing-jie
QJ
Fan
Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Guizhou University), Ministry of Education, Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, Guizhou Province, PR China.
Guang
G
Qiao
Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region (Guizhou University), Ministry of Education, Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, Guizhou Province, PR China. Electronic address: xpwensc@hotmail.com.
Xiao-Peng
XP
Wen
Guizhou Institute of Fruit Tree Science, Guiyang 550006, Guizhou Province, PR China.
Tao
T
Liu
Guizhou Institute of Fruit Tree Science, Guiyang 550006, Guizhou Province, PR China.
Zhi-Jun
ZJ
Peng
Guizhou Institute of Fruit Tree Science, Guiyang 550006, Guizhou Province, PR China.
Yong-Qiang
YQ
Cai
D000595:Amino Acid Sequence; D029421:Cactaceae / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D002374:Catalase / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D058639:Cold-Shock Response / Q000235:genetics; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics*
D010940:Plant Proteins; D006861:Hydrogen Peroxide; D002374:Catalase
Abiotic stress; Catalase activity; Gene expression; HuCAT; Pitaya