Joanne Chory is a member of the National Academy of Sciences, the American Academy of Sciences and Arts, a foreign member of the Royal Academy of Sciences, a foreign member of the French Academy of Sciences, and an academician of the German Academy of Sciences. She is currently an HHMI researcher, director of the Salk Institute of Biology, and a professor at UCSD. A master-level scholar in the field of botany, countless PIs have emerged from her laboratory, including a large number of Chinese scholars who are now active in the field of plant hormone signal transduction and came from her laboratory (Li Jianming, Zhao Yunde, Wang Zhiyong, Wang Xuelu wait). Her laboratory has made huge contributions to plant light signal transduction and brassinosteroid signaling pathways, and her total papers have been cited more than 50,000 times.

Professor Qiao Li’s major scientific discoveries include but are not limited to: 1) The discovery of a brassinosteroid signal transduction pathway that is completely different from that of animals; 2) They discovered about 30,000 genes in Arabidopsis thaliana About 90 are all expressed at high levels at a certain time of day, and this time changes with the seasons. If we can seize this time point, it will be of great benefit to agricultural production; 3) They discovered a signaling pathway for how plants respond to shade, which is also of great significance to agricultural production. They are described below.

1. Brassinosteroid signaling pathway

Brassinosteroid is the sixth major class of plant hormones (auxins, cytokinins, gibberellins, abscission acids and ethylene), which was discovered 40 years ago. Mitchell et al. (1970) found that rapeseed pollen extract could promote stem elongation and cell division, and reported this finding in Nature. Later, Grove et al. (1979) isolated a steroid-like molecule. It was the first brassinosteroid hormone to be isolated. It was not until 1997 that Professor Chory and his colleagues (Professor Li Jianming, Li Jianming - Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences) first discovered the receptor for this hormone (Li and Chory, 1997), and a series of subsequent works clarified The entire pathway by which plants sense this type of hormone. It is worth mentioning that Professor Wu Guang of Shaanxi Normal University (School of Life Sciences, Shaanxi Normal University, SNNU) has collaborated with Professor Qiao Li and made important contributions to elucidating this signaling pathway.

2. How plants adjust their growth rhythm according to the light cycle

People have long discovered that plants grow at different speeds during the day and night. Generally speaking, plants grow wildly during the day and stay dormant at night. If you think about this process carefully, it will involve three processes: the plant's perception of light, the plant's biological clock, and the growth of the plant under the control of hormones. Exactly how these processes work is not yet completely answered by scientists. A series of work by Professor Jory made important contributions to elucidating this process (Micheal et al., 2008). They found that cis-acting elements such as CACATG exist upstream of most plant hormone-related genes, which allows them to be mobilized simultaneously at a certain point in time. It is the lighting conditions that perform the coordinating function!

3. How plants respond to "shade"

The third finding is similar to the second. The living environment of plants is often harsh, and competition is the best manifestation of this harshness. Modern agriculture involves intensive planting, resulting in smaller and smaller living spaces for each individual plant. It can be imagined that in a densely grown corn field, each corn plant hopes to grow faster than its peers so that it can intercept more sunlight. So how do plants sense that they are already living in the "shadow" of their companions and thus speed up their growth? The paper published by Professor Qiao Li and his colleagues in Cell in 2008 (Tao et al., 2008) answered this question: when plants are in the shade, the gene encoding TAA1 protein will be highly expressed. TAA1 is an aminotransferase that catalyzes the reaction from L-tryptophan to 3-indolepyruvate, which is the first step in the synthesis of auxin.

Plants thus grow taller rapidly under the action of auxin.

Author: Rodiola

Source: Zhihu