Projects
Our lab work on mites that are agricultural pests and focuses on several aspects of research, primarily related to mite-plant interactions. We use molecular tools such as DNA and RNA isolation and sequencing, confocal microscopy using immunostaining and FISH methods as well as, in the near future, proteomic tools to investigate the various questions we still have about mites from different families.
Our current main research topics are:
1. Insecticide resistance aspects in Tetranychus urticae.
Tetranychus urticae or the Two-Spotted Spider Mite (TSSM) is the most economically devastating herbivore mite pest worldwide. It is able to feed on hundreds of different plant crop species. Though having a very small genome, it has highly expanded metabolic gene families which enable it to digest a variety of xeno-chemicals: be it plant secondary metabolites or pesticides. Its short generation time and reproductive characteristics add to its ability to develop pesticide resistance at a remarkable rate. In our lab, we study several aspects of those abilities:
- We survey TSSM samples from all over Israel, with the help of Israeli ministry of agriculture’s extension services, collecting TSSM samples where and whenever an outburst is reported. Those are tested for resistance to over 10 different pesticides.
- Life history tables, reproductive behaviour and fitness of selected susceptible and resistant field-collected populations is studied.
- Known markers to different pesticides are tested.
2. The interplay between heat and pesticide resistance in TSSM.
As global warming becomes more and more felt worldwide, we are observing its effects on plant pests. TSSM is highly resistant to warm temperatures and show improved fitness in temperatures up to 35ﹾC. We are interested to study the effect heat exposures (short or long) may have on physiological fitness traits in TSSM, that is on its ability to be pesticides resistant. To this end, we subject TSSM females from different genetic backgrounds to various heat and pesticide regimes and record their life history traits for possible changes.
3. The effect of warming climates on plant resistance to TSSM.
Israel is a global warming hot spot, meaning the average yearly temperature is rising in Israel double than the global rise. This already has visible significant effects on the spread and damage caused by mites, specifically TSSM. We conduct several studies in the lab to test the effect of heat exposure on the performance of TSSM on various hosts. We hope to isolate plant genes that allow better resistance or resilience of the plant to TSSM in warm field conditions.
4. Circadian rhythms in plant feeding mites.
Circadian rhythms allow organisms to behave in accordance with the daily and seasonal conditions in which they are living. These circadian rhythms change based on environmental cues, such as photoperiod and temperature, to adapt to the constantly changing environment. Circadian rhythms were studied in the “model mite” TSSM on a seasonal scale: TSSM hibernates over the cold winter season. Adult, mated females enter hibernation when exposed to certain photoperiods at specific life stages. We wish to study possible daily rhythms in TSSM and uncover the genetic mechanisms governing these.
5.Broad mite effectors secreted to plant hosts affecting plant development.
The broad mite, Polyphagotarsonemus latus, is a serious pest in tropical and subtropical areas in the world. P. latus is a polyphagous mite that can feed on various species from both mono and di-cotyledonal plants. It is considered an extremely dangerous pest on annual crop plants. This is due to the deformation damage caused to the plant hosts; broad mite feeding can cause leaf deformation, dwarfing, flower lost and fruit- deformation. If not treated on time, the damage from the mites' feeding can last long after the mites have been dealt with. Our hypothesis is therefore that broad mite secrets molecules, also known as ‘effectors’, during feeding, into its plant host. We further hypothesize that those effectors are the ones causing the deformation seen in the plant, long after the mites have been killed.
Past and prospective research ventures:
1. Eriophyte mites in aubergine farming in Israel.
A new symptom caused by eriophyte mites was reported in 2017 in aubergine fields. Since then, it has spread throughout Israel and is causing increasing damage. The species of these mites is yet undetermined. In our lab, we wish to use genetic systematic tools to determine if this is a new identified species. The extent of the damage and symptoms created by these mites will also be determined.