Genetics to boost sugarcane production

Scientists in Brazil are taking steps towards genetically modifying sugar cane so it produces more sucrose naturally, looking to eventually boost the productivity and economic benefits of the tropical grass.

A man stacks sugarcane at the Ver-o-Peso (Check the Weight) market in Belem.

Currently, it is common for producers to raise sucrose levels in sugar cane by applying artificial growth regulators or chemical ripeners. This inhibits flowering, which in turn prolongs harvest and milling periods.

One of these growth regulators, ethephon, is used to manage agricultural, horticultural and forestry crops around the world. It is widely used to manipulate and stimulate the maturation of sugarcane as it contains ethylene, which is released to the plant on spraying.

Ethylene, considered a ripening hormone in plants, contributes to increasing the storage of sucrose in sugar cane.

“Although we knew ethylene helps increase the amount of sugar in the cane, it was not clear how the synthesis and action of this hormone affected the maturation of the plant,” said Marcelo Menossi, professor at the University of Campinas (Unicamp) and coordinator of the project, which is supported by the Brazilian research foundation FAPESP.

To study how ethylene acts on sugarcane, the researchers sprayed ethephon and an ethylene inhibitor, aminoethoxyvinylglycine (AVG), on sugar cane before it began to mature.
sucrose accumulation.jpg

After spraying both compounds, they quantified sucrose levels in tissue samples from the leaves and stem of the cane. They did this five days after application and again 32 days later, on harvest.

Those plants treated with the ethephon ripener had 60 per cent more sucrose in the upper and middle internodes at the time of harvest, while the plants treated with the AVG inhibitor had a sucrose content that was lower by 42 per cent.

The researchers were then able to identify genes that respond to the action of ethylene during ripening of the sugar cane. They also successfully identified the genes involved in regulating sucrose metabolism, as well as how the hormone acts on sucrose accumulation sites in the plant.

Based on the findings, the team has proposed a molecular model of how ethylene interacts with other hormones.

“Knowing which genes or ripeners make it possible for the plant to increase the accumulation of sucrose will allow us to make genetic improvements in sugarcane and develop varieties that over-express these genes, without the need to apply ethylene, for example,” explained Menossi.

This research could also help with spotting the most productive sugar cane, as some varieties that do not respond well to hormones, he added. “It will be possible to identify those [varieties] that best express these genes and facilitate the ripening action.”

Taken from a newsletter by FAPESP, a SciDev.Net donor, edited by our Latin America and the Caribbean desk

 

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Rise in groundwater overuse could hit food prices

By Neena Bhandari

[SYDNEY] The increasing use of groundwater for irrigation poses a major threat to global food security and could lead to unaffordable prices of staple foods. From 2000 to 2010, the amount of non-renewable groundwater used for irrigation increased by a quarter, according to an article published in Nature on March 30. During the same period China had doubled its groundwater use.

The article finds that 11 per cent of groundwater extraction for irrigation is linked to agricultural trade.

“In some regions, for example in Central California or North-West India, there is not enough precipitation or surface water available to grow crops like maize or rice and so farmers also use water from the underground to irrigate,” the article says.

“When a country imports US maize grown with this non-renewable water, it virtually imports non-renewable groundwater.”

Carole Dalin,  Institute for Sustainable Resources at University College, London

The article focused on cases where underground reservoirs or aquifers, are overused. “When a country imports US maize grown with this non-renewable water, it virtually imports non-renewable groundwater,” Carole Dalin, lead author and senior research fellow at the Institute for Sustainable Resources at University College, London, tells SciDev.Net.

Crops such as rice, wheat, cotton, maize, sugar crops and soybeans are most reliant on this unsustainable water use, according to the article. It lists countries in the Middle East and North Africa as well as China, India, Mexico, Pakistan and the US as most at risk.

“Pakistan and India have been locally most affected due to groundwater depletion and exporting agricultural products grown with non-sustainable groundwater. Iran is both exporting and importing and The Philippines is importing from Pakistan, which is non-sustainable. China is importing a lot from India. Japan and Indonesia are importing, mainly from the US,” says Yoshihide Wada, co-author of the report and deputy director of the International Institute for Applied Systems Analysis’s Water Programme, Laxenburg, Austria.

Agriculture is the leading user of groundwater, accounting for more than 80 to 90 per cent of withdrawals in irrigation-intense countries like India, Pakistan and Iran, according to the report.

The researchers say efforts to improve water use efficiency and develop monitoring and regulation need to be prioritised. Governments must invest in better irrigation infrastructure such as sprinkler irrigation and introduce new cultivar or crop rotation to help producers minimise water use.

Wada suggests creating awareness by putting water labels, along the lines of food labels, “showing how much water is used domestically and internationally in produce and whether these water amounts are from sustainable or non-sustainable sources”.

Andrew Western, professor of hydrology and water resources at the University of Melbourne’s School of Engineering, suggests enforceable water entitlement systems and caps on extraction. “In recent decades, water reform in Australia has led to water having a clear economic value made explicit by a water market. This has enabled shifts in water use to cope with short-term climate fluctuations and has also driven a trend of increasing water productivity,” he says.

This piece was produced by SciDev.Net’s Asia & Pacific desk.

 

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The State of the World’s Plants 2017 by Bursary Winner Harison Andriambelo

This week’s post was written by Harison Andriambelo, a PhD student at the University of Antananarivo, Madagascar. Harison was the awardee of the Early Career Researcher travel bursary from the Society for Experimental Biology in association with the Global Plant Council, enabling him to attend the State of the World’s Plants Symposium at the Royal Botanic Gardens, Kew. Here’s how he got on!

Attending the State of the World’s Plants Symposium 2017 at the Royal Botanic Gardens, Kew, was a fantastic opportunity for me to get a detailed insight into many aspects of plant conservation, including the latest emerging research. Scientists from all over the world attended the symposium and shared results from several ecoregions, including tropical, boreal, and temperate biomes. It was also great to visit the Gardens, which were looking amazing in the British summertime.

As a botanist from Madagascar, I found the focus session on conservation in my country particularly useful, and I really enjoyed the talks by Pete Lowry and George Schatz, both from Missouri Botanic Garden.

Other sessions in the conference highlighted important issues including fires and invasive species. We heard that fire is not always bad for plants, especially in savannah systems, where plant diversity is maintained by the fire regime. I believe better scientific communication to the public is urgently needed on this issue.

Another great session concerned invasive species. I have worked across all the biomes in Madagascar, from humid forests to the dry spiny forest, and I have seen first-hand the effects invasive plants can have. A detailed assessment of invasive plant species in wetlands and in the western dry forests of Madagascar made me more aware of the potential impacts of these species. By attending this symposium, I learned about several programs and efforts by the Invasive Species Specialist Group and will spread information about invasive species management to colleagues once I return to Madagascar.

For me, the highlight of the session on medicinal plants was a talk by the President of Mauritius. It was inspirational to see that scientists can even become a head of state. Such leadership offers great promise for addressing environmental issues at national scale. I am certain that having an ecologist as President in Madagascar would allow much greater progress on conservation issues in my home country, which has many highly threatened endemic species. Scientists can bring their understanding and ability to analyze complex systems to bear on policy. Good leaders can take a long-term holistic view and accord the appropriate priority to the environment in national plans for development.

This symposium allowed me to present some results of my research activities in Madagascar and get feedback from an international group of scientists. A deep discussion with people working at RBG Kew about how to scale information on tree dispersal processes from the plot to landscape scales was very valuable. As they know the Madagascan context, they were very interested in my results and a possible collaboration is on its way.

Finally, this trip to London allowed me to spend more time with my colleague Dr Peter Long at the University of Oxford and to make good progress for my scientific research activities. I am very grateful to the Society for Experimental Biology for supporting my travel to the UK to participate in this meeting.