Annual Report 2013–14

In Search of Salt Tolerant Soybeans Prof. Lam Hon-ming ( left ), professor in the School of Life Sciences and director of the Centre for Soybean Research, has succeeded in identifying the gene that makes soybeans salt tolerant. This research is built on a significant discovery he made when he and his team decoded 31 soybean genomes in 2010 — wild soybeans have much higher biodiversity than cultivated ones and they may have retained genes that help them to fend for themselves in the natural environment. In this research, Professor Lam and his team extracted the salt-tolerance gene from wild soybeans using the latest technologies in genomics, genetics, and molecular biology. Their target was a wild-grown soybean that's been proved to be highly tolerant to salt. They named it W05. In salt treatment experiments, W05 survived. Professor Lam and his team then applied state-of-the-art whole genome sequencing to decode the W05 genome and to genotype, in other words, to determine the differences in the genetic makeup, of the population. The researchers managed to identify the positions of the main genes in 11 of the traits they observed. They also found an area in chromosome 3 of W05 that specifically controls salt tolerance. However there are dozens of genes in that area. Using a variety of methods, the team finally found their target gene. They transferred the target gene into plant cells using a transgenic approach, and found that those given the gene survived the salt treatment much better than those that were not, proving that the gene is in fact responsible for a plant’s salt tolerance. Professor Lam hopes to collaborate with research units in northeastern and northwestern China to obtain drought-tolerant and highly adaptive soybeans and apply the salt-tolerant gene to them, making them ‘super soy’ that can grow in the most adverse environments and improve the lives of poor farmers. The research was published in Nature Communications in July 2014. 尋找耐鹽大豆 生命科學學院教授兼大豆研究中心主任 林漢明（上圖） 發現能令大豆耐鹽的基 因。這研究乃以林教授2010年的發現為基 礎，當時他和研究團隊破解了三十一種大 豆基因組密碼，揭示野生大豆比人工培植 大豆有更高生物多樣性，並保存了耐逆基 因，以利於自然環境中 生長。 林教授應用了基因組學、 遺傳學和分子生物學的最 新技術，抽取野生大豆的 耐鹽基因。實驗對象是一 種已證實耐鹽程度極高的 野生大豆，稱為W05， 在鹽處理實驗下，W05抵 受住高鹽環境存活下來。 團隊以先進的全基因組測 序技術，對W05的基因組 和基因型進行解碼，亦即 找出這個種群的基因結構差異。 研究人員觀察到大豆的十一種特徵，成功 找到與它們相關的主效基因所處位置， 又發現在W05的三號染色體中有一個區域 專門主宰大豆的耐鹽程度，終於在該區域 幾十個基因當中找到目標基因。 研究人員接着以轉基因方法將目標基因放 進植物細胞，發現與沒有目標基因的植物相 比，注入該基因的植物較能抵受鹽處理而 存活，證明該基因確實負責控制植物的耐 鹽程度。 林教授希望可與中國西北或東北的研究單 位合作，取得耐旱和適應力強的大豆， 並加入耐鹽基因，培育出能在極惡劣環境 生長的「超級大豆」，改善貧農的生活。 人工培植大豆 Cultivated soybean（C08） 野生大豆 Wild-grown soybean（W05） 對照樣本 Control Sample 經鹽處理樣本 Salt-treated Sample 對照樣本 Control Sample 經鹽處理樣本 Salt-treated Sample 研究結果刊登於2014年7月的《自然通訊》。 21