Morphological characteristics, anatomical structure, and gene expression: novel insights into gibberellin biosynthesis and perception during carrot growth and development.
Gibberellins (GAs) are considered potentially important regulators of cell elongation and expansion in plants. Carrot undergoes significant alteration in organ size during its growth and development. However, the molecular mechanisms underlying gibberellin accumulation and perception during carrot growth and development remain unclear. In this study, five stages of carrot growth and development were investigated using morphological and anatomical structural techniques. Gibberellin levels in leaf, petiole, and taproot tissues were also investigated for all five stages. Gibberellin levels in the roots initially increased and then decreased, but these levels were lower than those in the petioles and leaves. Genes involved in gibberellin biosynthesis and signaling were identified from the carrotDB, and their expression was analyzed. All of the genes were evidently responsive to carrot growth and development, and some of them showed tissue-specific expression. The results suggested that gibberellin level may play a vital role in carrot elongation and expansion. The relative transcription levels of gibberellin pathway-related genes may be the main cause of the different bioactive GAs levels, thus exerting influences on gibberellin perception and signals. Carrot growth and development may be regulated by modification of the genes involved in gibberellin biosynthesis, catabolism, and perception.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University , Nanjing 210095, China.
Guang-Long
GL
Wang
Key Laboratories of Crop Genetics and Physiology of the Jiangsu Province and Plant Functional Genomics of the Ministry of Education, Yangzhou University , Yangzhou 225009, China.
Fei
F
Xiong
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University , Nanjing 210095, China.
Feng
F
Que
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University , Nanjing 210095, China.
Zhi-Sheng
ZS
Xu
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University , Nanjing 210095, China.
Feng
F
Wang
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University , Nanjing 210095, China.
Ai-Sheng
AS
Xiong