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Australian Herbicide Resistance Initiative (AHRI)

Rare but predictable – A new target-site mutation for glyphosate resistance discovered

Tag Archives | mechanisms

Australian Herbicide Resistance Initiative (AHRI)

Rare but predictable – A new target-site mutation for glyphosate resistance discovered

AHRI’s principal research fellow, Dr Qin Yu, in collaboration with other international researchers, has demonstrated that in Tridax daisy, glyphosate resistance is associated with the Thr-102 site mutation alone. In contrast to earlier investigations with goosegrass, where both the Pro-106 and Thr-102 sites (TIPS) mutation endowed glyphosate resistance, this study has demonstrated that selection for a mutation at Thr-102 alone can lead to moderate level glyphosate resistance in the field.

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Australian Herbicide Resistance Initiative (AHRI)

Metabolic trifluralin resistance

Just when we thought we understood the mechanism of trifluralin resistance we blink and find another. Earlier in the year, we reported on research by AHRI PhD student Jinyi Chen confirming that a target site mutation that infers resistance to trifluralin. Earlier in the year, we reported on research by AHRI PhD student Jinyi Chen confirming that a target site mutation that infers resistance to trifluralin. Now Jinyi has confirmed that metabolic resistance to trifluralin is also possible.

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Australian Herbicide Resistance Initiative (AHRI)

‘Clear and present danger’ – glyphosate resistance in the North

Researchers and growers have long been anticipating glyphosate resistance in the Northern cropping region and now the preliminary results from the first herbicide resistance survey in the region are confirming the ‘clear and present danger’ facing the grains industry. While growers have previously enjoyed the ‘freedom’ to use this herbicide as their go-to, highly effective tool for weed control, there’s now strong evidence that they should look for ways to protect this mode of action and implement a variety of tools such as the double knock, rotating herbicides and seed bank management as a matter of urgency.   

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Australian Herbicide Resistance Initiative (AHRI)

Alphabet cross-resistance in South Australia

Alarming herbicide resistance news has come out of South Australia. A population of ryegrass from the Eyre Peninsula, SA has been confirmed resistant to all of the pre-emergent herbicides – Avadex, Arcade, Trifluralin, Propyzamide and Sakura, as well as two lesser-known herbicides. It was sampled in 2014 just two years after the release of Sakura in Australia. You guessed it, metabolic cross-resistance is at play. What’s most concerning is a random survey in the South East of SA found many more populations of ryegrass with multiple cross-resistance to a range of pre-emergent herbicides. The perplexing thing is that there’s no predictable…

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Australian Herbicide Resistance Initiative (AHRI)

GST – a tax on herbicide molecules

When you buy a birthday cake, the goods and services tax (GST) makes the cost of the cake bigger.  If only Mr Hewson could have explained it so succinctly he may have been Prime Minister! There’s another type of GST in plants that do the same thing to herbicide molecules. It makes them bigger and then the whole thing gets smashed to pieces. The GST in plants are enzymes called glutathione-S-transferase.  In other words, they join or transfer the big molecule glutathione onto other molecules. Click through to learn more!

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Australian Herbicide Resistance Initiative (AHRI)

Digging deep into 2,4-D resistance

Synthetic auxins might be the oldest kids on the herbicide block but that doesn’t mean they are well understood. In fact, there are very large knowledge gaps that researchers like AHRI’s Dr Danica Goggin are trying hard to fill in a bid to find ways to overcome resistance to this herbicide group in weeds such as wild radish.

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Australian Herbicide Resistance Initiative (AHRI)

AHRI insight – the 100 is up!

We’re undecided whether we should picture the AHRI communication team cutting through a massive banner as we run onto the ground or raising our bats in the air at the MCG after a long day in the middle. It’s been a long innings and is one that we have enjoyed immensely. To celebrate the 100th AHRI insight we’re reflecting on what have been the big stories that got you excited and made the biggest impact.

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Australian Herbicide Resistance Initiative (AHRI)

How trifluralin resistance works

Do you know what a microtubule is? If you could dream up the most complex way to make a tube, microtubules are it! Assembling a microtubule is about as complex as assembling a car, and there are thousands of them in every cell, in every living thing. If you aren’t super interested in the detail, all you need to know is that trifluralin kills plants by binding to microtubules and stopping cell division. AHRI researcher Qin Yu and her team of Chinese PhD students have recently identified the exact mutation in microtubules that stops trifluralin binding to them and causes…

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Heping Han

Australian Herbicide Resistance Initiative (AHRI)

Glyphosate resistance and plant fitness

Things that affect your fitness: Christmas – go on, have one more serving of trifle, it is only wafer thin! Television – for example, spending five full days watching the Boxing Day test match cricket. Each on their own are not too bad, but put them together and we have a problem. Things that affect plant fitness: The TIPS mutation that causes high-level glyphosate resistance. The TIPS mutation is a double mutation of the glyphosate target site, the 102 and the 106 mutation. The 106 mutation has been found in a number of species and has no fitness penalty associated…

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Australian Herbicide Resistance Initiative (AHRI)

Selfish weeds can manipulate the nitrogen cycle to suit themselves

Weeds are selfish, self-centred, narcissistic, manipulative pieces of work that will do whatever it takes to make themselves look good and make the other plants around them look bad. Some weeds are so self-obsessed that they can manipulate the soil nitrogen into a form that is just the way they like it. New research by Cathryn O’Sullivan from CSIRO is showing that some weeds release chemicals from their roots that slow down the bacteria that are essential to the nitrogen cycle, retaining nitrogen in the ammonium form that weeds can potentially take up faster than crop plants. Totally selfish! Click…

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