Abstract
BACKGROUND: Periwinkle (Catharanthus roseus L.) is a significant source of two valuable anticancer alkaloids, vincristine and vinblastine. Amino acids serve as precursors for alkaloid biosynthesis, and environmental stresses are known to induce an increase in the ratio of secondary metabolites in plants. This study was conducted using a completely randomized design with a factorial arrangement and three replications at the Khuzestan Agricultural Sciences and Natural Resources University under controlled greenhouse conditions. The experimental factors included foliar application of the amino acid tryptophan at varying concentrations (control, 50, 100, 150, 200, and 250 ppm) and drought stress levels (100%, 70%, and 40% of field capacity). RESULTS: Results from the mean comparisons indicated that increasing the concentration of tryptophan up to 250 ppm, in conjunction with maintaining soil moisture at 40% of field capacity, exerted a positive and significant effect on the biochemical and physiological parameters of both root and aerial organs. Data analysis revealed that all measured traits exhibited significant enhancements at elevated tryptophan concentrations (250 ppm), culminating in an 87% increase in plant dry weight, a 105% in root dry weight, and a 66% in total protein compared to the control group. The activity of enzymatic antioxidants, including catalase (CAT) and peroxidase (POX), in tryptophan-inoculated plants subjected to severe drought stress demonstrated increases of 844% and 650%, respectively, relative to control plants. Conversely, the imposition of severe drought stress (40% field capacity) resulted in a substantial decrease in plant dry weight, total protein, and photosynthetic pigments. However, these conditions also facilitated an increase in the concentrations of the alkaloids vinblastine and vincristine, as well as the levels of non-enzymatic antioxidants. Collectively, these results highlight the potential of using the amino acid tryptophan as a sustainable and environmentally friendly approach to enhance drought tolerance in periwinkle, offering promising implications for agricultural practices in arid and semi-arid regions. CONCLUSIONS: Ultimately, the application of tryptophan at concentration 250 ppm was effective in alleviating the adverse impacts of drought stress by enhancing dry weight, photosynthetic pigments, and antioxidant enzyme activities in the periwinkle plant, culminating in increases in vincristine and vinblastine levels by 193% and 138%, respectively, under severe drought stress (40% field capacity).
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Claims 11
Claim · model-written summary
Tryptophan up to 250 ppm under 40% field capacity positively affected root and aerial biochemical and physiological parameters.
- Taxon
- periwinkle plant (Catharanthus roseus L.)
Catharanthus roseust0 - Organ / stage
- root and aerial organse0
- Treatment
- tryptophan up to 250 ppme0
- Outcome
- biochemical and physiological parameterse0
- Direction
- positivee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“increasing the concentration of tryptophan up to 250 ppm, in conjunction with maintaining soil moisture at 40% of field capacity, exerted a positive and significant effect on the biochemical and physiological parameters of both root and aerial organs”
Claim · model-written summary
Tryptophan at 250 ppm increased plant dry weight by 87% relative to control.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- tryptophan concentrations (250 ppm)e0
- Outcome
- plant dry weighte0
- Direction
- increasee0
- Value
- 87%e0
- Comparator
- control groupe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“all measured traits exhibited significant enhancements at elevated tryptophan concentrations (250 ppm), culminating in an 87% increase in plant dry weight, a 105% in root dry weight, and a 66% in total protein compared to the control group”
Claim · model-written summary
Tryptophan at 250 ppm increased root dry weight by 105% relative to control.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- tryptophan concentrations (250 ppm)e0
- Outcome
- root dry weighte0
- Direction
- enhancementse0
- Value
- 105%e0
- Comparator
- control groupe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“all measured traits exhibited significant enhancements at elevated tryptophan concentrations (250 ppm), culminating in an 87% increase in plant dry weight, a 105% in root dry weight, and a 66% in total protein compared to the control group”
Claim · model-written summary
Tryptophan at 250 ppm increased total protein by 66% relative to control.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- tryptophan concentrations (250 ppm)e0
- Outcome
- total proteine0
- Direction
- enhancementse0
- Value
- 66%e0
- Comparator
- control groupe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“all measured traits exhibited significant enhancements at elevated tryptophan concentrations (250 ppm), culminating in an 87% increase in plant dry weight, a 105% in root dry weight, and a 66% in total protein compared to the control group”
Claim · model-written summary
Catalase activity increased 844% with tryptophan under severe drought.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- tryptophan-inoculatede0
- Outcome
- catalase (CAT)e0
- Direction
- increasese0
- Value
- 844%e0
- Comparator
- control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“The activity of enzymatic antioxidants, including catalase (CAT) and peroxidase (POX), in tryptophan-inoculated plants subjected to severe drought stress demonstrated increases of 844% and 650%, respectively, relative to control plants”
Claim · model-written summary
Peroxidase activity increased 650% with tryptophan under severe drought.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- tryptophan-inoculatede0
- Outcome
- peroxidase (POX)e0
- Direction
- increasese0
- Value
- 650%e0
- Comparator
- control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“The activity of enzymatic antioxidants, including catalase (CAT) and peroxidase (POX), in tryptophan-inoculated plants subjected to severe drought stress demonstrated increases of 844% and 650%, respectively, relative to control plants”
Claim · model-written summary
Severe drought decreased plant dry weight, total protein and photosynthetic pigments.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- severe drought stress (40% field capacity)e0
- Outcome
- plant dry weight, total protein, and photosynthetic pigmentse0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“the imposition of severe drought stress (40% field capacity) resulted in a substantial decrease in plant dry weight, total protein, and photosynthetic pigments”
Claim · model-written summary
Severe drought increased vinblastine, vincristine and non-enzymatic antioxidants.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- severe drought stress (40% field capacity)e1
- Outcome
- concentrations of the alkaloids vinblastine and vincristinee0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“these conditions also facilitated an increase in the concentrations of the alkaloids vinblastine and vincristine, as well as the levels of non-enzymatic antioxidants”
e1“the imposition of severe drought stress (40% field capacity)”
Claim · model-written summary
Severe drought increased non-enzymatic antioxidants.
- Taxon
- periwinkle plant (Catharanthus roseus L.)Catharanthus roseust0
- Treatment
- severe drought stress (40% field capacity)e1
- Outcome
- levels of non-enzymatic antioxidantse0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“these conditions also facilitated an increase in the concentrations of the alkaloids vinblastine and vincristine, as well as the levels of non-enzymatic antioxidants”
e1“the imposition of severe drought stress (40% field capacity)”
Claim · model-written summary
Tryptophan at 250 ppm increased vincristine by 193% under severe drought.
- Taxon
- periwinkle plante0
- Treatment
- tryptophan at concentration 250 ppme0
- Outcome
- vincristinee0
- Direction
- increasese0
- Value
- 193%e0
Not reportedComparator
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“the application of tryptophan at concentration 250 ppm was effective in alleviating the adverse impacts of drought stress by enhancing dry weight, photosynthetic pigments, and antioxidant enzyme activities in the periwinkle plant, culminating in increases in vincristine and vinblastine levels by 193% and 138%, respectively, under severe drought stress (40% field capacity)”
Claim · model-written summary
Tryptophan at 250 ppm increased vinblastine by 138% under severe drought.
- Taxon
- periwinkle plante0
- Treatment
- tryptophan at concentration 250 ppme0
- Outcome
- vinblastinee0
- Direction
- increasese0
- Value
- 138%e0
Not reportedComparator
Verbatim
t0“periwinkle plant (Catharanthus roseus L.)”
e0“the application of tryptophan at concentration 250 ppm was effective in alleviating the adverse impacts of drought stress by enhancing dry weight, photosynthetic pigments, and antioxidant enzyme activities in the periwinkle plant, culminating in increases in vincristine and vinblastine levels by 193% and 138%, respectively, under severe drought stress (40% field capacity)”
The same questions in other papers
tryptophan · growth · Catharanthus roseus (Madagascar periwinkle)Positive and negative results
5 papers in the same direction as this paper · 1 in the opposite direction
- positive
- no effect
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3 papers more in this group
See all 7 papers →tryptophan · quality: protein · Catharanthus roseus (Madagascar periwinkle)Results agree
1 paper in the same direction as this paper
- positive
drought · molecular: metabolites · Catharanthus roseus (Madagascar periwinkle)Results differ
3 papers in the same direction as this paper · 3 in the opposite direction
- negative
- no effect
- positive
3 papers more in this group
See all 7 papers →drought · quality: phytochemicals · Catharanthus roseus (Madagascar periwinkle)Results agree
1 paper in the same direction as this paper
- positive
drought · physiology: photosynthesis · Catharanthus roseus (Madagascar periwinkle)Results agree
2 papers in the same direction as this paper
- negative
- negative
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.