erucifoline N-oxide showed a weak correlation between leaf surface and leaf tissue.
A positive correlation was also found for the total concentration of total PA, total free
bases, while such a correlation was absent for senecionine-like PAs or N-oxides of
PAs (Table 2).
There are only a few other studies that have demonstrated differences between
the profiles of leaf-tissue and leaf-surface SMs. For instance, Brooks and Feeny [45]
suggested that the different patterns in the leaf-tissue and leaf-surface chemical
profiles of Daucus carota could be related to the seasonal variation. BadenesPerez et al. reported that glucosinolate and saponin profiles differed between foliage
and leaf surface of the Barbarea spp., B. napus, and N. officinale [20].
Moreover, the glucosinolate profile on the leaf surface revealed differences from
that in leaf tissue of A. thaliana plants [21].
6
Conclusions
Great diversity of PAs was found in many plants, especially in Jacobaea and Senecio
plants.
Leaf-tissue PA variation was determined by genetics, but also influenced
by environmental factors. Few studies have been conducted to investigate the leafsurface PA variations. According to the previous work on J. vulgaris plants and the
Jacobaea hybrid plants, leaf-surface and leaf-tissue PA profiles of a particular
genotype were different from one another: a number of PAs that were present
in the leaf tissue at relatively high concentrations, such as jaconine and usaramine
N-oxide, were absent from the leaf surface. Nevertheless, positive correlations were
found for the concentration of all PAs, that of the free bases, as well as that of
a number of jacobine- and otosenine-like PAs between the leaf surface and leaf
tissue. Moreover, the total amount of PAs present on the surface of the leaves was
less than 0.01% of the total amount present in the leaf tissue. This makes it clear that
the relationship between the leaf-surface and leaf-tissue SMs can offer an important
new angle to the study the insect-plant interaction mediated by plant SMs.
Acknowledgments Dr. Klaas Vrieling, Dr. Patrick P. J. Mulder, Dr. Prof. Eddy van der Meijden,
and Dr. Prof. Peter G. L. Klinkhamer are thanked for their help in writing this MS. We are grateful to
the Fundamental Research Funds for the Central Universities (CUG130411) and National Natural
Science Foundation of China (No.31570537 and 31200425) for their financial support.
References
1. Hadacek F (2002) Secondary metabolites as plant traits: current assessment and future perspectives. Crit Rev Plant Sci 21:273–322
2. Hartmann T (2007) From waste products to ecochemicals: fifty years research of plant
secondary metabolism. Phytochemistry 68:2831–2846
3. Hartmann T (2008) The lost origin of chemical ecology in the late 19th century. Proc Natl Acad
Sci 105:4541
4. Fraenkel GS (1959) The raison d'etre of secondary plant substances. Science 129:1466
11 Variation in Leaf-Surface and Leaf-Tissue Secondary Metabolites:. . .
259
A positive correlation was also found for the total concentration of total PA, total free
bases, while such a correlation was absent for senecionine-like PAs or N-oxides of
PAs (Table 2).
There are only a few other studies that have demonstrated differences between
the profiles of leaf-tissue and leaf-surface SMs. For instance, Brooks and Feeny [45]
suggested that the different patterns in the leaf-tissue and leaf-surface chemical
profiles of Daucus carota could be related to the seasonal variation. BadenesPerez et al. reported that glucosinolate and saponin profiles differed between foliage
and leaf surface of the Barbarea spp., B. napus, and N. officinale [20].
Moreover, the glucosinolate profile on the leaf surface revealed differences from
that in leaf tissue of A. thaliana plants [21].
6
Conclusions
Great diversity of PAs was found in many plants, especially in Jacobaea and Senecio
plants.
Leaf-tissue PA variation was determined by genetics, but also influenced
by environmental factors. Few studies have been conducted to investigate the leafsurface PA variations. According to the previous work on J. vulgaris plants and the
Jacobaea hybrid plants, leaf-surface and leaf-tissue PA profiles of a particular
genotype were different from one another: a number of PAs that were present
in the leaf tissue at relatively high concentrations, such as jaconine and usaramine
N-oxide, were absent from the leaf surface. Nevertheless, positive correlations were
found for the concentration of all PAs, that of the free bases, as well as that of
a number of jacobine- and otosenine-like PAs between the leaf surface and leaf
tissue. Moreover, the total amount of PAs present on the surface of the leaves was
less than 0.01% of the total amount present in the leaf tissue. This makes it clear that
the relationship between the leaf-surface and leaf-tissue SMs can offer an important
new angle to the study the insect-plant interaction mediated by plant SMs.
Acknowledgments Dr. Klaas Vrieling, Dr. Patrick P. J. Mulder, Dr. Prof. Eddy van der Meijden,
and Dr. Prof. Peter G. L. Klinkhamer are thanked for their help in writing this MS. We are grateful to
the Fundamental Research Funds for the Central Universities (CUG130411) and National Natural
Science Foundation of China (No.31570537 and 31200425) for their financial support.
References
1. Hadacek F (2002) Secondary metabolites as plant traits: current assessment and future perspectives. Crit Rev Plant Sci 21:273–322
2. Hartmann T (2007) From waste products to ecochemicals: fifty years research of plant
secondary metabolism. Phytochemistry 68:2831–2846
3. Hartmann T (2008) The lost origin of chemical ecology in the late 19th century. Proc Natl Acad
Sci 105:4541
4. Fraenkel GS (1959) The raison d'etre of secondary plant substances. Science 129:1466
11 Variation in Leaf-Surface and Leaf-Tissue Secondary Metabolites:. . .
259