Table 1 Anti-fungal activity and toxicity of MALCs.

From: A lipophilic cation protects crops against fungal pathogens by multiple modes of action

 

C12-G+

C18-NMe3+

C18-SMe2+

Effects in Z. tritici

   Depolarisation of the plasma membranea

2.15

3.38

2.98

   Fragmentation of mitochondriab

4.12

1.12

1.25

   Depolarisation of mitochondriab

0.28

0.11

0.20

   Inhibition of ATP synthesisc

19.84

54.23

58.66

   Cell mortalityd

32.29

89.27

66.47

Effect on human cells

   Fragmentation of mitochondriab

26.13

35.58

35.26

   Inhibition of respirationb

12.97

9.89

9.90

   Cytotoxicity (MTT assay, C109)b

2.32

4.13

3.53

   Cytotoxicity (MTT assay, HepG2)b

0.99

2.42

3.67

   Relative mitochondrial toxicitye

54.21

88.71

47.86

Toxicity in zooplankton

   Daphnia magna survivalf,b

0.31

1.61

2.42

   Relative toxicityg

10.01

143.73

160.86

Phytotoxicityh

   Leaf symptoms in wheat

>1000

>1000

>1000

   Leaf symptoms in rice

>1000

>1000

>1000

Anti-fungal protection

   Protection against Septoria leaf blotchi

5

1.57

0.22

   Protection against rice blast diseasej

17.19

12.45

2.67

   Inhibition of M. oryzae germinationb

0.83

0.77

0.76

   Induction of plant defencek

5.46

0.80

14.83

  1. aPercentage of depolarised cells (DiBAC4(3)-positive) after treatment with ~50-times the EC50-value for depolarisation of mitochondria; note one-way ANOVA testing reveals no difference to control (1.95%).
  2. bConcentration (µg ml−1) at 50% effect (EC50) after 30–45 min treatment. Values were estimated graphically from non-linear regression curves and corrected for the molecular weight of their counter ions; all curves were based on data from 2–3 experiments.
  3. cPercent reduction of ATP in cell extracts after 2 h incubation with 5 µg ml−1 MALC; statistically different to control with P = 0.0146 (C12-G+), P = 0.0049 (C18-SMe2+), P = 0.0068 (C18-NMe3+).
  4. dPercentage of dead Z. tritici cells in liquid cultures after 24 h incubation at 10 µg ml−1.
  5. eQuotient of EC50 values for inhibition of human and fungal respiration.
  6. fNumber of immobile/non-responsive water fleas at EC50 after 24 h.
  7. gMortality in Z. tritici multiplied by mortality in Daphnia, indicates equivalence in toxicity.
  8. hLowest concentration (µg ml−1) at which chlorosis occurs after 7 days incubation.
  9. iMean area with pycnidia (%; wheat, sprayed with 100 µg ml−1, infected, assessed after 21 days).
  10. jMean lesion area (%; rice treated with 125 µg ml−1, infected and assessed after 4 days).
  11. kDAB-stained leaf area after 6 h treatment with 100 µg ml−1, given as percent of positive control.