Why do leeks have a special flavor

Liu Ning (middle) instructs graduate students to analyze the growth of hydroponic leeks in the greenhouse of the Vegetable Center of Beijing Academy of Agriculture and Forestry Sciences.

However, compared with bulk vegetables such as cabbage, eggplant, cabbage, tomato, etc.

Recently, the Vegetable Center of Beijing Academy of Agriculture and Forestry Sciences (hereinafter referred to as the Vegetable Center) has systematically identified and analyzed the key genes in the process of flavour synthesis of leek through transcriptomics technology, clarified the synthesis pathway, and initially outlined the road map , Laid a solid work foundation for in-depth research on the regulation mechanism of leek flavor synthesis.

Clarify the way of flavor formation

Leek is a perennial perennial root vegetable of the Allium family of Allium subfamily distributed in East Asia and Southeast Asia.

"Leek, garlic, onion, green onion, etc.

However, the current research on CSO synthesis and its decomposition pathways mainly focus on garlic and onion.

They clarified the entire path of leeks from sulfur transport, absorption and utilization, to synthesis of flavor substances.

Key genes for characteristic aroma formation

The amazing thing is that CSO has no taste, so how does it make leeks so "smell"?

Liu Ning introduced that allium plants are extremely rich in alliinase, which is a key enzyme for the release of characteristic aromas.

In fact, the two are separated from each other under normal conditions.

It is worth mentioning that the team members used high-throughput sequencing technology to systematically analyze the tissue-specific transcriptomes of leek leaves, flowers, inflorescences, rhizomes, roots and seeds.

"Enhancing the flavor" of hydroponic leeks

On the market, leeks can be said to make consumers "love and fear", and the topic of excessive pesticide residues in leeks one after another.

In response to the problem of excessive pesticide residues in leeks, the vegetable center researcher Wu Zhanhui and his team launched a hydroponic leeks production model.

However, hydroponic leeks have encountered a bottleneck problem.

“The main reason is that the accumulation of CSO is significantly lower than that of soil-cultured leeks in the same crop.

Inspired by the farmer’s proverb “Yield in good times, quality in adversity”, researchers after repeated trials and screening found that adding an appropriate amount of salt to the original nutrient solution formula precisely controls the stress level of hydroponic leek, which can promote the transcription of key enzyme genes in the process of CSO synthesis.

This improvement measure can realize the "flavor enhancement" of hydroponic leek, which is expected to develop into a low-cost, simple and practical cultivation technique, and has the potential to be applied to improve the flavor and quality of other hydroponic vegetables.
The molecular mechanism behind this cultivation technique is under study.

At present, hydroponic leek technology has been demonstrated and promoted in Beijing suburbs, Dingzhou, Hebei, Xinxiang, Henan, and Aksu, Xinjiang, and has achieved good economic, ecological and social benefits.
(Source: China Science News Zhang Qingdan)

Related paper information: https://doi.
org/10.
1016/j.
ygeno.
2021.
05.
005