Influence of NR gene inhibition on cell senescence and growth and development

To understand function of NR gene roundly and get new breeding material, the NR gene was down-regulated by antisense inhibition and the reaction of physiological and growth and development were roundly researched in nr mutants of tomato. The result shows that the wild-type fruits (wt) have higher level of expression of NR gene than nr1, nr2, nr3, nr4. Ethylene synthesis of all mutants was much lower than of wt in all fruit ripening stage. The transpiration rate, stomatal conductance and cell membrane permeability were higher and respiration rate was lower in nr1, nr2 than in wt plants and intercellular CO2 concentration was higher in nr1 than in wt with T1 leaves. The number of branches was less and the length of internode and diameter of stem was more in nr lines than in wt. The color changes were substantially delayed in mutant fruits. The mutant fruit in nr1, nr2 reached the breaker stage of development at approximately 7 weeks, 7-9 days delayed compared with wt. The fruit of nr1, nr2 reached the hypermature stage of development at approximately 12.5 weeks, 37-38 days delayed compared with wt. The rot percent and weight loss percent of fruits was lower and the stem pull force was stronger in nr1 than in wt in room store. The result could be relative to interplay of receptors and functionally redundant of ethylene receptors.