Banana lovers rejoice – Israeli company develops bug-resistant bananas

Dr. Eli Khayat: We recently conducted field trials, growing plants in an area heavily infested with nematodes, and the plants showed complete resistance. They weren’t affected at all.If you eat five bananas a week, there’s a good chance that one …

Dr. Eli Khayat: We recently conducted field trials, growing plants in an area heavily infested with nematodes, and the plants showed complete resistance. They weren’t affected at all.If you eat five bananas a week, there’s a good chance that one of them has its genetic origins in Israel.

Driving north of Nahariya towards the Lebanese border, you pass fields and fields of banana crops at nearby Achziv as well as on Kibbutz Rosh Hanikra. It’s at the latter kibbutz where biotech company Rahan Meristem (1998) LTD, a world leader in banana biotechnology, has its offices and laboratories.

“We’re the largest producer of banana tissue cultured plants in the world – producing about 10 million a year. They’re sold all around the world. We calculated that approximately 20% of the bananas that are marketed throughout the western world originated or were selected at Rahan,” said Dr. Eli Khayat, head of research and development at Rahan and a professor of plant biology at Hebrew University and the Technion.

“Most of our research is on bananas – trying to improve the quality of the crop – using molecular genetics to breed bananas that ripen slower and have a longer shelf life,” he told ISRAEL21c. “These are parameters which are important to both the grower and the consumer. Our goal is to breed plants, and given that bananas are seedless, the only means to produce elite clones is by genetic engineering.”

With a total production of approximately 60 million tons per year, banana and plantains (bananas which are grown for cooking) have become a major crop worldwide, exported from tropical countries to almost every part of the globe. But as a result of its natural sterility, most banana varieties have yet to be genetically improved via biotechnological tools.

Now in a new breakthrough development with far-reaching implications, Khayat and his team have successfully completed a field trial that validates its latest accomplishment – the complete resistance of banana plants to a wide range of pathogenic nematodes – tiny microscopic worms that damage plants from their root.

Nematodes are considered one of the most destructive pathogens attacking bananas in all zones of production. Vegetative propagation, using infested corms or suckers, has disseminated this pest throughout the world. Yet, most effective nematicides have been banned in large parts of the world because of their polluting effect on the environment. As a result, nematode resistance is considered to be a highly attractive attribute that is estimated to reduce growers’ expenses by hundreds of millions of dollars every year.

According to Khayat, the accomplishment has taken six years of research and testing.

“The technology involved was developed jointly by Rahan, Bar Ilan University and Hazera, an Israeli seed company. The result is transgenic bananas, bananas that have been genetically modified. They are completely resistant to nematodes, by use of a special technology called RNAi,” he told ISRAEL21c.

“We recently conducted field trials, growing plants in an area heavily infested with nematodes, and the plants showed complete resistance. They weren’t affected at all. The nematodes couldn’t reproduce on the plants.”

Founded in 1974 by members of the kibbutz, Rahan Meristem was the first operating commercial tissue culture laboratory in Israel. It was established as an extension of an existing well-recognized fruit trees nursery in Israel.

Initially, Rahan’s workers developed new procedures for large scale, in vitro, clonal propagation of over 200 plant genera including ornamental, industrial, fruit and vegetable crops.

By the mid 1980s the company focused on a smaller variety of plants, and in vitro propagated banana plants became the leading product. Combined with the high level of pre-existing expertise of banana agrotechnology on Kibbutz Rosh Hanikra, Rahan became a center of research and consultation for the banana industry throughout the world.

A formal R&D department was established in 1991 in order to provide technical support to the different branches of the company and develop new products and technologies, as well as other technical services. Khayat joined the company in 1992 when he returned to Israel from a post as associate professor at Rutgers.

When Khayat talks about molecular genetics and how it relates to bananas, it sounds like the Israeli kibbutz of yesterday – with oranges, dancing, and tractors, has turned into a futuristic science fiction mystery.

“We’re producing and breeding banana plantlets from tissue culture. They’re banana clones. Bananas are seedless so the only way to improve them is by selection, a process we work on at our premises on the kibbutz. The selected clones are propagated by means of tissue culture. You can amplify a single clone to as many as you want,” Khayat explained.

When the topic is cloning and genetic engineering, Khayat knows that he’s treading in controversial territory, with large movements around the world opposed to genetically engineered food. But he provides thoughtful explanations as to why he thinks Rahan is on the right path.

“I think the opposition derives from a general view about genetically engineered plants as being unknown and a mystery. It’s the same as the feelings about vaccines at the beginning of the 20th century – the view that it will cause something worse that what it’s protecting against,” he said.

“Genetic engineering is much safer than insecticides to both the environment and to humans, but politically, it’s a problem with environmental groups. For example, in general the fields where bananas are grown are treated with nematicides to avoid infestation by nematodes. The volume of insecticide could not only kill humans, but even elephants. They are very nasty chemicals, and the damage to the environment as a result is very heavy.”

“With transgenic plants, especially bananas due to the fact that they can’t cross-fertilize and don’t have seeds, there’s no dissipation of the genetic material anyway – it’s contained within the plant. So there’s no danger to humans or to the environment. The plants can grow in areas that weren’t treated with insecticides.”

Khayat pointed out that in Costa Rica, where much of the population works in the banana industry, there was a large occurrence of male sterility due to nematicides. He added that over time, many countries have accepted genetically engineered food products as a fact on the ground.

“In the US, it’s a standard practice. In Europe, by and large, there is still objection, but it’s slowly breaking down. Now in Spain and Germany, the import of transgenic seeds is allowed, but it’s still case by case.”

Rahan’s nematode-resistant technology must now pass through a regulatory process in the US which is very expensive, and Khayat acknowledges that Rahan, which employs 130, will not be able to carry this out alone.

As a result, the company is currently looking for strategic partners in the US who will take over the process. The company is also looking for partners in the banana industry, such as Dole, Chiquita and Del Monte, who might be interested in developing Rahan’s technology. Khayat admits that negotiations with one of these two banana giants is now underway.