Tomato salt-resistant gene 'lost and recovered'

soil is the cornerstone of food security. However, in recent years, due to the overuse of fertilizer and pesticides, soil ecological conditions are much worse than before, the basic soil force has decreased, and the problem of salinization of cultivated land has become particularly prominent.
addition to "treating" saline, scientists are also working hard to tap the salt-resistant potential of crops. Recently, Zhu Health, a researcher at the Shanghai Research Center for Plant Adversity Biology of the Chinese Academy of Sciences (hereinafter referred to as the "Center for Adversity"), and Huang Sanwen, a researcher at the Agricultural Genomics Research Institute of the Chinese Academy of Agricultural Sciences (Shenzhen), worked together to find the salt-resistant gene that has been lost in modern tomatoes, providing a new technical solution for molecular breeding of salt-resistant crops.
research was published online online in the international journal The Journal of the European Society for Molecular Biology.present, land salinization has become a worldwide problem, the global saline area of up to 956 million hectares, and China's saline land area is large, widely distributed, a total area of about 100 million hectares. This headache of saline land, in fact, is china's farmland reserve development resources, is the potential guarantee land for grain production.
" to tap the salt-resistant potential of crops and improve their salt resistance is one of the important ways to solve food safety problems. Huang Sanwen, co-author of the paper, told China Science Daily that tomatoes are the world's highest-yielding vegetables and are known as "the world's largest vegetable crop" and have important economic value.
, tapping the salt-resistant potential of tomatoes became their goal. The first step in this is to explore where tomatoes come from.
" tomato originated in the Andes region of South America, as humans migrated, tomatoes also 'break' from the south to the north, about reach central America and Mexico, humans basically completed the domestication of tomatoes, so that tomatoes from small fruit into large fruit, about the 16th century after the arrival in Europe, and spread around the world. Zhu Guangtao, the paper's first author and a professor at Yunnan Normal University, told China Science Daily.
, the big fruit-cultivated tomatoes we eat today are domesticated from wild tomatoes. In the origin of tomatoes, some wild materials grow near the sea, such as local wild currant tomatoes can grow in a higher salt environment, tomato ancestors are actually salt-resistant.
, however, in the process of domestication and breeding, humans pay more attention to the size of tomato fruit, and their ancestral salt-resistant skills are gradually lost. Now, the tomatoes we can eat on the market are basically no longer of this quality.
important to recover the salt-resistant genes of wild tomatoes., Huang Sanwen's team has sequenced the whole genome of different types of tomatoes, established a "great treasure trove" of tomato species resource information, and established an important position in tomato genomics research in China.
" has a rich library of species, as well as a wealth of wild materials, it is on this basis, we have the opportunity to dig up the presence of tomatoes 'unknown' skills. Wang Zhen, the first author of the paper and a Ph.D. from the Shanghai Center for Adversity, told China Science Daily that they found some interesting phenomena through genome analysis and esolysis of 369 tomato materials.
" In determining the root system of these tomato materials and the content of sodium and potassium ions in the above-ground part, we found that in the three groups of wild currant tomatoes, cherry tomatoes and cultivated tomatoes, the ratio of sodium and potassium ions in the roots was increased one by one, and the higher the salt resistance, the worse the sodium-potassium ratio. Zhu Health, co-author of the paper, told China Science Daily.
through genome-wide correlation analysis, they were lucky to find several more significant signal bits, the strongest of which appeared in the frontal region of chromosome 4, where a "carpet"search found a key gene, SlHAK20.
" gene encodes a known potassium ion transporter, which we found also has sodium ion transport activity and is a sodium potassium ion transporter. Wang Zhen introduced.
studies have shown that the right amount of potassium ions is the mineral nutrient necessary for plant growth and development, while sodium ions inhibit plant growth and development. SlHAK20, as a sodium potassium ion transporter, plays a vital role in reducing the damage of sodium ions to plants.
genomic analysis showed that the SlHAK20 gene was strongly domesticated, and that the gene's starting crycoin corresponded to the loss of a fragment of six bases at the 48th base downstream of the base, resulting in a significant reduction in salt resistance to cultivated tomatoes. In wild tomatoes, the presence of this fragment can make SlHAK20 transport sodium ion activity become stronger, is an important reason for salt resistance in wild tomatoes.
In addition, "we also found that the SlHAK20 gene has a broad spectrum, in the case of rice, knocking out two of the same genes in rice, SlHAK20, OsHAK4 and OsHAK17, may also lead to rice sensitivity to salt stress." Zhu said this means that the function of SlHAK20 isogenal response salt stress in single and twin leaf crops is conservative, and specific molecular mechanisms need to be studied in depth.the "key" to the SlHAK20 gene, researchers can unlock the "open way" of many tomatoes.
" China's arable land area is relatively tight, in order to make efficient use of saline land, in variety selection, we can achieve variety upgrading, purposefully cultivate some tomatoes with certain anti-salt characteristics, so that the reuse of agricultural farmland can play an important supporting role. Zhu Guangtao said.
For example, China's eastern coastal areas have a large population density, land supply is tight, these areas have a large coastal saline land, can be "wasted into treasure", so that salt-alkali land and tomatoes collide out of the "spark", to achieve its due value.
and whether other crops can also change their salt-resistant qualities in this way is also a research focus.
" in the process of screening large fruits, salt-resistant genes are lost, we want to 'optimize' tomato selection in the next, so that tomatoes not only retain the 'advantage' of large fruits, but also salt-resistant properties. Zhu said that the relevant research work is currently under way.
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