Physiological Mechanisms Underlying Tassel Symptom Formation in Maize Infected with <i>Sporisorium reilianum</i>
Yuhe Wang,
Chuzhen Xu,
Yansong Gao,
Yanhua Ma,
Xiaoming Zhang,
Lin Zhang,
Hong Di,
Jinxin Ma,
Ling Dong,
Xing Zeng,
Naifu Zhang,
Jiawei Xu,
Yujuan Li,
Chao Gao,
Zhenhua Wang,
Yu Zhou
Affiliations
Yuhe Wang
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Chuzhen Xu
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Yansong Gao
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Yanhua Ma
Institute of Forage and Grass land Sciences, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China
Xiaoming Zhang
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Lin Zhang
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Hong Di
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Jinxin Ma
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Ling Dong
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Xing Zeng
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Naifu Zhang
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Jiawei Xu
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Yujuan Li
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Chao Gao
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Zhenhua Wang
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Yu Zhou
Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region, Engineering Technology Research Center of Maize Germplasm Resources Innovation on Cold land of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China
Head smut is a soil-borne fungal disease caused by Sporisorium reilianum that infects maize tassels and ears. This disease poses a tremendous threat to global maize production. A previous study found markedly different and stably heritable tassel symptoms in some maize inbred lines with Sipingtou blood after infection with S. reilianum. In the present study, 55 maize inbred lines with Sipingtou blood were inoculated with S. reilianum and classified into three tassel symptom types (A, B, and C). Three maize inbred lines representing these classes (Huangzao4, Jing7, and Chang7-2, respectively) were used as test materials to investigate the physiological mechanisms of tassel formation in infected plants. Changes in enzyme activity, hormone content, and protein expression were analyzed in all three lines after infection and in control plants. The activities of peroxidase (POD), superoxide dismutase (SOD), and phenylalanine-ammonia-lyase (PAL) were increased in the three typical inbred lines after inoculation. POD and SOD activities showed similar trends between lines, with the increase percentage peaking at the V12 stage (POD: 57.06%, 63.19%, and 70.28% increases in Huangzao4, Jing7, and Chang7-2, respectively; SOD: 27.01%, 29.62%, and 47.07% in Huangzao4, Jing7, and Chang7-2, respectively. These were all higher than in the disease-resistant inbred line Mo17 at the same growth stage); this stage was found to be key in tassel symptom formation. Levels of gibberellic acid (GA3), indole-3-acetic acid (IAA), and abscisic acid (ABA) were also altered in the three typical maize inbred lines after inoculation, with changes in GA3 and IAA contents tightly correlated with tassel symptoms after S. reilianum infection. The differentially expressed proteins A5H8G4, P09233, and Q8VXG7 were associated with changes in enzyme activity, whereas P49353, P13689, and P10979 were associated with changes in hormone contents. Fungal infection caused reactive oxygen species (ROS) and nitric oxide (NO) bursts in the three typical inbred lines. This ROS accumulation caused biofilm disruption and altered host signaling pathways, whereas NO signaling triggered strong secondary metabolic responses in the host and altered the activities of defense-related enzymes. These factors together resulted in the formation of varying tassel symptoms. Thus, interactions between S. reilianum and susceptible maize materials were influenced by a variety of signals, enzymes, hormones, and metabolic cycles, encompassing a very complex regulatory network. This study preliminarily identified the physiological mechanisms leading to differences in tassel symptoms, deepening our understanding of S. reilianum-maize interactions.
