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Article|12 May 2023|OPEN
Spatiotemporal profiles of gene activity in stamen delineate nucleo-cytoplasmic interaction in a male-sterile somatic cybrid citrus
Nan Jiang1 , Meng-Qi Feng1 , Lai-Chao Cheng1 , Li-Hua Kuang1 , Chao-Chao Li1 , Zhao-Ping Yin1 , Rong Wang1 , Kai-Dong Xie1 , Wen-Wu Guo1,2 , Xiao-Meng Wu,1 ,
1National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
2Hubei Hongshan Laboratory, Wuhan 430070, China
*Corresponding author. E-mail:

Horticulture Research 10,
Article number: uhad105 (2023)
Views: 110

Received: 04 Mar 2023
Accepted: 08 May 2023
Published online: 12 May 2023


Cytoplasmic male sterility (CMS) has long been used to produce seedless fruits in perennial woody crops like citrus. A male-sterile somatic cybrid citrus (G1 + HBP) was generated by protoplast fusion between a CMS callus parent ‘Guoqing No. 1’ Satsuma mandarin (Citrus unshiu, G1) and a fertile mesophyll parent Hirado Buntan pummelo (Citrus grandis, HBP). To uncover the male-sterile mechanism of G1 + HBP, we compared the transcriptome profiles of stamen organ and cell types at five stages between G1 + HBP and HBP, including the initial stamen primordia, enlarged stamen primordia, pollen mother cells, tetrads, and microspores captured by laser microdissection. The stamen organ and cell types showed distinct gene expression profiles. A majority of genes involved in stamen development were differentially expressed, especially CgAP3.2, which was downregulated in enlarged stamen primordia and upregulated in tetrads of G1 + HBP compared with HBP. Jasmonic acid- and auxin-related biological processes were enriched among the differentially expressed genes of stamen primordia, and the content of jasmonic acid biosynthesis metabolites was higher in flower buds and anthers of G1 + HBP. In contrast, the content of auxin biosynthesis metabolites was lower in G1 + HBP. The mitochondrial tricarboxylic acid cycle and oxidative phosphorylation processes were enriched among the differentially expressed genes in stamen primordia, meiocytes, and microspores, indicating the dysfunction of mitochondria in stamen organ and cell types of G1 + HBP. Taken together, the results indicate that malfunction of mitochondria-nuclear interaction might cause disorder in stamen development, and thus lead to male sterility in the citrus cybrid.