A healthy cure for citrus greening

June 2019

For more than ten years, a majority of orange groves in Florida have been afflicted with 'citrus greening'.  The disease has devastated millions of acres of citrus crops throughout America and elsewhere.

The visual symptoms of citrus greening include short internodes (stem length between leaves), tiny leaves, asymmetric chlorosis (loss of green colour in leaves), flowering out of season, and leaf and fruit shedding.

Trees that succumb to this disease produce fruits that are green, misshapen and bitter.  They're unsuitable for sale as fresh fruit or for juice.  Most affected trees die within a few years.

Research into citrus greening has consumed well over $540 million of funding without a single recovered orange or cured tree to show for it.

How to create unhealthy apples

March 2014

Image Creative Commons

Ever thought of the humble apple as a staple health-food?  Not in the USA it seems. 

Exports of American apples (and pears) to Europe have dropped 73% over the last five years.  The culprit lies in the high levels of two pesticides added to wax coatings to prevent 'scald'.

 

'Scald' is a post-harvest storage disorder of apples resulting in discoloured patches on the fruits' skin due to damage and death within the surface layer of cells. The cause seems to be long-term storage, especially under unsuitably humid conditions. Similar-looking post-harvest blemishes may arise due to pesticide treatments, sun, or friction damage in the case of very ripe fruit.

Now, there's another problem looming on the other side of the Atlantic.  Two varieties of GM 'Arctic' apples which don't turn brown when damaged looks set to be approved by the USDA. 

What use is purple GM juice?

March 2014

Commentary 

Anthocyanins are anti-oxidant plant pigments credited with wide-ranging therapeutic effects. 

Support for the well-accepted role of anthocyanins in folk medicine the world over has since been confirmed by epidemiology and, more recently, by an increasing body of science. 

Many research trials have demonstrated anthocyanins' marked ability to inhibit tumour formation and cancer-cell proliferation.  Protection from cardio-vascular disease and age-related neuro-degenerative disorders have been clearly shown in scientific studies. 

Enter 'genetically-improved' tomatoes, turned purple by their newly acquired ability to generate anthocyanins and thereby re-jigged to make everyone healthy. 

Red not purple

March 2014

Red vine tomato. CC image by Mrs Gemstone on Flickr

Although tomatoes have naturally high levels of many nutrients with health benefits, adding in a further class of anti-oxidants not naturally present has been a holy grail of genetic engineers since the 1990s. 

Such genetically-improved tomatoes would, it is hoped, conveniently piggy-back the already high consumption of tomatoes in the modern diet, and make up for the failure of the official '5-a-day for health' message. 

The anti-oxidants of interest are 'anthocyanins', which are the dark pigment in the skin of many fruits and vegetables, such as blueberries and aubergines.   

Science has indicated that:

“intake (of anthocyanins) in the human diet is associated with protection against coronary heart disease and an improvement in sight.  They might also prevent cholesterol-induced atherosclerosis, could have anti-inflammatory and anti-carcinogenic activities and could aid the the prevention of obesity and diabetes” (Gonzali).  

The health benefits described above have emerged from studies using black-currants, blueberries, tart cherries, elderberries, grape juice and seed, purple corn, purple sweet potato, red soyabeans, red beans and red wine. 

Botox apples

June 2011

Photo from Flickr

The US Department of Agriculture (USDA) has received its first request for approval of a GM apple.

Currently, sliced apples to be sold fresh are rinsed in acids to prevent browning of the flesh and “maintain freshness” (you can do much the same at home with a little fruit juice).

Gene-silencing technology developed in Australia to prevent potatoes browning when cut has been licensed by a Canadian biotech company and applied to apples, for sale in America. The aim of the ever-white apple is to reduce processing costs and make apples more amenable to producers of ready-meals and children's lunch-boxes.