1 . Scientists have shown how plants can protect themselves against genetic (基因的) damage caused by environmental stresses. The growing tips of plant roots and shoots have an in-built mechanism (机制) that spells cell death if DNA damage is detected, avoiding passing on faulty DNA.
Plants have small populations of stem cells (干细胞) at the tips of their roots and shoots, which enable them to continuously grow and produce new tissues throughout their lifetime. These stem cells serve as ancestors for plant tissues and organs. However, any genetic faults present in the stem cells will continue to exist and be passed on permanently throughout the plant’s life, which could last thousands of years.
Given the critical role of stem cells and their exposure to potentially dangerous environments at the growing tips of roots and shoots, safeguards are necessary to prevent stem cell faults from becoming fixed. Researchers Nick Fulcher and Robert Sablowski, funded by the Biotechnology and Biological Sciences Research Council, aimed to uncover these protective mechanisms. Through experiments involving X-rays and chemicals, they discovered that stem cells were more sensitive to DNA damage compared to other cells.
When DNA damage occurs, the cells have the capacity to detect it and cause programmed cells to die, preventing the propagation of the damaged genetic code to the rest of the plant tissues. This process has similarities to the safeguard mechanism found in animal cells, which has been broadly studied due to its relevance in preventing cancer.
The identification of a similar protective system in plants is of great interest in the field of plant development. It also helps scientists develop plants that can better handle environmental stress. So knowledge of how plants deal with these stresses is of fundamental significance to agricultural science’s response to climate change.
1. What is the function of the in-built mechanism in plants?| A．To produce more roots and shoots. | B．To increase the overall lifetime of the plant. |
| C．To enhance plant growth and nutrient intake. | D．To stop genetic faults in stem cells passing on. |
| A．They are relatively abundant in quantity. | B．They are resistant to environmental stresses. |
| C．They make quick response to DNA damage. | D．They have the ability to repair damaged DNA. |
| A．Spread. | B．Change. | C．Existence. | D．Self-repair. |
| A．The way of dealing with climate change on the earth. |
| B．The significance of identifying the protective system in plants. |
| C．The method of ensuring plant survival under environmental stress. |
| D．The urgency of developing plants that can handle environmental stress. |
