Newsletter No. 443

443 • 19.9.2014 5 博文貫珍 The Galleria The Genomic Process 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. ‘Say we selected 96 types of soybean. Each type has 20 chromosomes. Does each chromosome carry the father’s gene or the mother’s?’ he explains. ‘Genetic research in the past used molecular markers, which had very low resolution. But now we can do genetic sequencing on the soybean and find out with far greater accuracy how the father’s and the mother’s genes are distributed in the offsprings.’ But how do they find the salt-tolerant gene from the haystack of genetic material? The scientists collected data over a number of years from both farmlands and greenhouses. ‘It’s another tedious process because we need to discount the effects of the natural environment which may change from year to year,’ said Professor Lam. ‘We observed and measured the traits of the soybeans, such as the size of the seeds and how salt-tolerant they are. Then we used bioinformatics to read the data and try to identify links between the genetic makeup of the plants and their performance in the field.’ Zooming in 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. To make sure that the phenomenon they observed is not restricted to W05 and C08, the team applied the same tests to other soybean germplasms, both wild and cultivated, and found that all salt-tolerant soybeans possess the same gene while in salt-sensitive soybeans, the gene has undergone mutation and lost its function irrevocably. Plants that grow on fertile and well-irrigated lands, mutate to get rid of that gene in order to conserve resources. Proving with Molecular Biology The team’s next step was to prove, using molecular biology, that the gene is in fact responsible for a plant’s salt tolerance. 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. They also inserted the gene into the roots of the C08 plant, and at the same time, added an unrelated gene into another C08 sample. Comparing the two, they found that the target gene performed much better in surviving salt treatment and offered far greater protection to its host. This has two implications,’ Professor Lam explains, ‘First, it means we can protect plants from salt at a cellular level. Second, it means we can influence the accumulation of sodium ion. Sodium ion is one of the major components of salt, and it is toxic. Once it enters a plant cell, it affects 為何不只種植野生大豆？ Why Not Just Grow Wild Soybeans? 農夫不喜歡野生大豆的好些特質： Some characteristics of wild soybeans make them unattractive to farmers: •種子太小 The seeds are small •屬於攀緣植物，於地上四處蔓生，難以用現時的機器收割 They are creepers that grow laterally on the ground, which makes them impossible to harvest with existing machinery •含油量較培植品種少 They generally have a lower oil content than cultivated varieties physical function. We discovered that the target gene was able to lower the level of sodium ion in the plant.’ Looking Ahead 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. 聯合書院於1956年6月由廣僑、光夏、華僑、文化及平正會計 專科學校五所私立書院合併組成，於同年10月正式開課。書 院早期的經濟來源主要是學術機構的補助及學費。從第一 學年預算所見，書院估計：孟氏基金會的補助加上學費收益 達到港幣四十餘萬元，扣除教職員薪酬開支及校舍租金後， 每月仍有盈餘二百五十元，應能達到收支平衡。 事實上，聯合書院開辦初年，實際收入遠未能達到預算， 儘管一直縮緊開支，每月平均赤字竟達萬元，只好靠師生艱 苦撐持。1959年，香港政府宣布資助聯合、崇基、新亞三所 書院，以籌備成立中文大學，聯合書院的財政才有可觀的 改善。 聯合書院慷慨借出第一學年預算原件，現於大學展覽廳 展出。 Founded in 1956 through the amalgamation of five colleges: Canton Overseas, Kwang Hsia, Wah Kiu, Wen Hua, and Ping Jing College of Accountancy, United College commenced operation in October of the same year. In its early days, the College's revenue came mainly from tuition fees and financial support from educational organizations. The College’s Proposed Budget for the First Academic Year shows that it expected to receive an income of about HK$400,000 from funding from Mencius Educational Foundation and tuition fees. After paying salaries for teachers and staff as well as the rent for its premises, etc., there would be an estimated surplus of HK$250 per month. However, the College’s actual income fell short of its expectations in its fledgling years. The College ran a monthly deficit of some 10,000 dollars despite its austerity measures. Its finances were improved only after the Hong Kong Government announced the provision of subventions to United College, Chung Chi College, and New Asia College in 1959, a year after the proposal for establishing the Chinese University was accepted. The Proposed Budget for the First Academic Year of United College is now on display in the University Gallery, courtesy of the College.