Characterization of MADS-box gene family and its unique response to drought and nickel stresses with melatonin-mediated tolerance in dragon fruit (Selenicereus undatus L.)
Liu Hui,
Darya Khan,
Aamir Ali Khokhar,
Zhang You,
Wei Lv,
Babar Usman,
Qamar U Zaman,
Hua-Feng Wang
Affiliations
Liu Hui
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China
Darya Khan
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China
Aamir Ali Khokhar
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China
Zhang You
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China
Wei Lv
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China
Babar Usman
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China
Qamar U Zaman
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China; Corresponding authors at: School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China.
Hua-Feng Wang
School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China; Collaborative Innovation Center of Nanfan and High-Efficiency Tropical Agriculture, School of Tropical Crops, Hainan University, Haikou 70228, China; Corresponding authors at: School of Breeding and Multiplication, Hainan Yazhou Bay Seed Laboratory, Hainan University, Sanya 572025, China.
Dragon fruit (pitaya) is an important tropical crop with medicinal and industrial values. However, severe environmental stress factors affect dragon fruit production and development. The MADS-box gene family performs essential role in the regulation of stress tolerance, reproduction, and fruit ripening in various plants, but relevant studies haven't been conducted on dragon fruit. In this study, the identification and expression analysis of the MADS-box gene family was conducted in response to abiotic stress factors in pitaya seedlings. We identified 67 MADS-box genes distributed across 11 chromosomes of the pitaya genome. All the genes were named from HuMADS-1 to HuMADS-67. The phylogenetic tree of HuMADS-box genes was constructed together with soybean, wheat, and Arabidopsis. Based on the phylogenetic analysis, tree tropology and motif's structure, all the genes were divided into 3 groups as Mα, Mδ, and MIKC. The HuMADS genes showed a conserved intron-exon structure and motif domain organization. The expression patterns of all HuMADS-box genes varied in 15 tissues of pitaya. The analysis of subcellular localization of all proteins predicted that 55.8 % of the total gene members were localized in the nucleus. The syntenic analysis showed 28 collinearity gene pairs, in which 4 gene pairs showed tandem duplication and 24 pairs showed segmental duplication on the chromosomes. Cis-acting element predicted their regulatory roles in plant defense processes. RNA-seq analysis of pitaya seedlings under single and combined stresses of drought and nickel exhibited higher expression of HuMADS-box genes. In addition, several HuMADS genes showed enhanced expression in response to melatonin treatment under drought and nickel stresses, thereby enhancing pitaya seedlingsgrowth and development. To validate the RNA-Seq data, RT-qPCR analysis was performed on 12 HuMADS genes, our results revealed that six of them (HuMADS-14/15/22/62/63/67) play important role in abiotic stress tolerance. Overall, our findings offer key insights for future genetic engineering strategies to develop stress-tolerant pitaya genotypes.
