Abstract
ABA is a plant signalling-molecule that plays a key role in regulating stomatal response, stress-tolerance responses, and coordinated growth of roots and shoots. Knowledge of the relationship between endogenous ABA level and plant growth is essential for improving plant growth and productivity. The wild-type tomato Rheinlands Ruhm (RR) and its flacca mutant were grafted in order to determine the relationship between endogenous ABA levels and biomass production. The flacca genotype is an ABA-deficient mutant, characterized by high stomatal conductance during the day or the night, high transpiration rate, marked tendency to wilt, and smaller size. Flacca scions grafted on to wild-type rootstock (Fs/Wr) exhibited higher ABA levels, lower transpiration rate, and higher water content than those of a control graft of flacca scion on flacca rootstock (Fs/Fr). Fs/Wr exhibited a lower ABA concentration, xylem exudate rate, ABA xylem-loading rate, and dry weight biomass in wild-type rootstock than in control grafts of wild-type scion on wild-type rootstock (Ws/Wr). Flacca rootstock grafted to wild-type scion (Ws/Fr) showed a higher ABA level, xylem exudation rate, ABA xylem-loading rate, dry weight biomass and length than grafts to flacca scion (Fs/Fr). Ws/Fr did not induce significant changes in wild-type scion as compared with Ws/Wr. In double grafts, flacca shoot fresh weight was significantly increased in flacca scion and wild-type scion grafted on to flacca rootstock (Fs + Ws/Fr) or wild-type rootstock (Fs + Ws/Wr). There was a significant linear relationship between biomass and ABA in scions (r=0.997, P=0.001). These results support the notion that ABA increases growth of tomato seedlings via improved stomatal control.
Original language | English |
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Pages (from-to) | 1329-1335 |
Number of pages | 7 |
Journal | Functional Plant Biology |
Volume | 29 |
Issue number | 11 |
DOIs | |
State | Published - 1 Jan 2002 |
Keywords
- ABA concentration
- Rootstock
- Scion
- Tomato graft
- Vegetative growth
ASJC Scopus subject areas
- Agronomy and Crop Science
- Plant Science