Fruit-specific V-ATPase suppression in antisense-transgenic tomato reduces fruit growth and seed formation.
The vacuole is a large, multifunctional organelle related to the processes of cell expansion, solute accumulation, regulation of cytoplasmic ion concentrations, pH homeostasis and osmoregulation, which are directly or indirectly achieved by vacuolar H+-pumps: vacuolar H+-ATPase (V-ATPase; EC 3.6.1.3) and vacuolar H+-pyrophosphatase (V-PPase; EC 3.6.1.1). In this study, we produced antisense-transgenic tomatoes (Lycopersicon esculentum L.) of the V-ATPase A subunit, which is under the control of the fruit-specific 2A11 promoter. One beta-glucuronidase (GUS)-transgenic line (GUS control) and seven A subunit antisense-transgenic lines were obtained. The amount of V-ATPase A subunit mRNA in fruit decreased in all antisense-transgenic lines, but in leaves showed no difference compared with the GUS control line and the nontransformant, suggesting that suppression of the V-ATPase A subunit by a 2A11 promoter is limited to fruit. The antisense-transgenic plants had smaller fruits compared with the GUS control line and the nontransformant. Surprisingly, fruits from the antisense-transgenic plants, except the fruit that still had relatively high expression of A subunit mRNA, had few seeds. Sucrose concentration in fruits from the antisense-transgenic plants increased, but glucose and fructose concentrations did not change. These results show the importance of V-ATPase, not only in fruit growth, but also in seed formation and in sugar composition of tomato fruit.
Amemiya
Tsuyoshi
T
Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, 464-8601 Nagoya, Japan.
Kanayama
Yoshinori
Y
Yamaki
Shohei
S
Yamada
Kunio
K
Shiratake
Katsuhiro
K
D016375:Antisense Elements (Genetics); D015152:Blotting, Northern; D050260:Carbohydrate Metabolism; D005638:Fruit / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism; D005966:Glucuronidase / Q000378:metabolism; D018551:Solanum lycopersicum / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D030821:Plants, Genetically Modified / Q000201:enzymology* / Q000254:growth & development; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D025262:Vacuolar Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*
D016375:Antisense Elements (Genetics); D012333:RNA, Messenger; D005966:Glucuronidase; D025262:Vacuolar Proton-Translocating ATPases