1 . When micro-plastics end up in farm fields, the pollution can damage plant growth. But two young researchers now report that combining fungi (真菌) with certain farm wastes can partly overcome that problem.
May Shin, 20, and Jiwon Choi, 18, met in a research design class at the Fryeburg Academy, a high school in Maine. May had desired to explore how micro-plastics might affect the ecosystem. Jiwon was crazy about plants and fungi. The young scientists cooperated to test how long-lived plastics might affect farm crops.
Scientists have shown certain fungi can aid root growth and a plant’s nutrient uptake. Those organisms are named arbuscular mycorrhizal fungi (AMF). Certain farm wastes, like straw, can provide nutrients to plants and help stabilize their roots. Such wastes are also known as mushroom substrate (基质) and people often grow mushrooms in them.
May and Jiwon planted over 2,000 scallion (大葱) seeds in pots of soil. Half the seeds got soil polluted with micro-plastics. The rest grew in plastic-free soil. The plants then were further divided into four groups. The young scientists added AMF to the soil in one group. Another group had a top layer of mushroom substrate. A third group got both treatments. The last group got none. For three weeks, the pair tracked how many scallions sprouted (发芽) in each group and measured the plants’ height once each week.
About twice as many scallions sprouted in clean soil compared to that containing plastic bits. But among plants surviving in the polluted soil, a combination of AMF and mushroom substrate helped them out. Those getting both treatments grew 5.4 centimeters per week. That was faster than either of the treatments alone or those getting none.
Jiwon and May then looked at the plant roots with a microscope. Where AMF had been added, it grew into those roots. That increased the scallion roots’ surface area, May said, which should promote their uptake of nutrients. So “I see this project as coming up with a sustainable solution for plant growth in polluted soils,” said May.
1. Why did May and Jiwon work together?| A．To see the effects of long-lived plastics on farm crops. |
| B．To find the relationship between plants and fungi. |
| C．To design a research on the growth of plants. |
| D．To explore the way that the ecosystem works. |
| A．To prove the existence of micro-plastics. | B．To compare fungi with farm wastes. |
| C．To tell the advantages of farm wastes. | D．To provide some related information. |
| A．Its purpose. | B．Its design. | C．Its findings. | D．Its reasons. |
| A．By keeping the plants more resistant to pollution. | B．By allowing the plants’ deep area more freedom. |
| C．By making nutrients more available to the plants. | D．By exposing the roots to a larger surface area. |
2 . Both humans and animals possess the ability to cry out for help when endangered or threatened. Plants, as it turns out, can too.
“We found that plants usually emit (发出) sounds when they are under stress and that each plant and each type of stress is associated with a specific identifiable sound,” researchers from Tel Aviv University in Israel wrote in their findings, published in the scientific journal Cell. “While undetectable to the human ear, the sounds emitted by plants can probably be heard by various animals, such as bats, mice, and insects.”
Stressors like dehydration (脱水) and damage to leaves gave rise to the plants’ high-pitched (尖声的) cries, which ranged from 20 to 250 kHz. The bigger the danger, the more frequent a plant’s signals. “Unstressed plants emitted less than one sound per hour, on average,” researcher Lilach Hadany said, “while the stressed plants — both dehydrated and injured — emitted dozens of sounds every hour.”
To catch these sounds, Hadany’s team surrounded tomato and tobacco plants with super-sensitive microphones. They then fed the data into an artificial intelligence program that could tell the difference between the species of plant and the types of sounds produced.
“Our findings suggest that the world around us is full of plant sounds, and that these sounds contain information,” Hadany wrote. She added that to translate that information, we just need the “right tools such as sensors that tell growers when plants need watering.” Doing so, researchers noted, may allow farmers to judge exactly when and where to water crops. Saving water, increasing harvests, and lowering stress for both plant and humankind.
1. What did researchers from Tel Aviv University in Israel find?| A．Creatures tend to cry out for help when in danger. |
| B．Plants can give off sounds when they are stressed. |
| C．Plant sounds can be heard by both animals and humans. |
| D．Plants make the same sound whatever type of stress they have. |
| A．The influence of stress on plants. |
| B．The urgency of relieving stress of plants. |
| C．The possibility of plants emitting sounds. |
| D．The importance of conducting the research. |
| A．To help get rid of plant stress. |
| B．To identify the types of stress. |
| C．To collect sounds emitted by plants. |
| D．To analyze the collected sounds of plants. |
| A．The research is of practical value. |
| B．It’s difficult to understand plant sounds. |
| C．Further research is needed in the future. |
| D．It’s as easy as pie for farmers to grow crops. |
3 . Animals can adapt quickly to survive unfavorable environmental conditions. Evidence is mounting to show that plants can, too. A paper published in the journal Trends in Plant Science details how plants are rapidly adapting to the effects of climate change, and how they are passing down these adaptations to their offspring(后代).
Plants are facing more environmental stresses than ever. For example, climate change is making winters shorter in many locations, and plants are responding. “Many plants require a minimum period of cold in order to set up their environmental clock to define their flowering time,” says Martinelli, a plant geneticist at the University of Florence. “As cold seasons shorten, plants have adapted to require shorter periods of cold to delay flowering. These mechanisms allow plants to avoid flowering in periods when they have fewer opportunities to reproduce.”
Because plants don’t have neural(神经的) networks, their memory is based entirely on cellular(细胞的),molecular(分子的),and biochemical networks. These networks make up what the researchers call somatic memory(体细胞记忆). “It allows plants to recognize the occurrence of a previous environmental condition and to react accordingly,” says Martinelli.
These somatic memories can then be passed to the plants’ offspring via epigenetics(表现遗传). “Several examples demonstrate the existence of molecular mechanisms modulating plant memory to environmental stresses and affecting the adaptation of offspring to these stresses,” says Martinelli.
Going forward, Martinelli hopes to understand even more about the genes that are being passed down. “We are particularly interested in decoding the epigenetic alphabet without changes in DNA sequence(序列),”he says. “This is especially important when we consider the rapid climate change, we observe today that every living organism, including plants, needs to quickly adapt to survive.”
1. What adaptations have plants made to shortened cold seasons?| A．They have shortened their flowering time. |
| B．They have got more chances to reproduce. |
| C．They have avoided flowering in cold seasons. |
| D．They have adjusted their environmental clock. |
| A．It is entirely based on neural networks. |
| B．It can help the plants’ offspring to survive. |
| C．It can help relieve environmental stresses. |
| D．It disturbs the plants’ biochemical networks. |
| A．Adjusting. | B．Treasuring. |
| C．Recording. | D．Sharing. |
| A．Plants are smart about flowering time |
| B．Plants can also adapt to climate change |
| C．Environmental stresses challenge plants |
| D．Mysteries of plant genes are to be unfolded |
A new study reveals that plants have their own “ bedtime alarm clock ” that helps them survive the night. Researchers at the University of York have discovered that plants possess an internal signal which they believe tells them
Plants’ ability to predict sunrise and estimate the
The researchers discovered a set of genes
5 . As we sip our coffee and read the daily headlines, climate changes can seem like a distant threat. But travel a few thousands miles to the source of your caffeine fix, and the threat is all too real.
The coffee farmers are now seeing violent downpours that drown their plants in Mexico, where the climate used to be stable and mild, but the temperature now see-saws between extreme cold and heat, which greatly affects their harvest. Unfortunately, farmers across South America, Asia and Africa are also watching coffee plants decrease as droughts and downpours attack their crops as a result of global warming. The consequences of all this could soon work their way through the pipeline to your local coffee shop.
The problem arises, in part, from refinement (改进) of our taste. Two main breeds of commercial coffee Arabica and Robusta gain special reputation. The former is by far the world’s favourite, accounting for about 70% of the coffee we drink. However, the Arabica plants have been bred from a very small stock taken from the mountains of Ethiopia-giving it very little genetic diversity and making it particularly difficult to adapt to climate change. Besides, the plant grows best between a very narrow range of relatively mild temperatures (18 to 22℃ ) and needs gentle, regular rainfall. The delicate Arabica plants just can’t cope with the new and unpredictable conditions that come with global warming.
All of these paint a depressing picture for the future. Researchers predict that the land suited to farming Arabica could drop by as much as 50% by 2050. Classic coffee-producing region, such as Vietnam, India and most of Central America, will be hit particularly hard. Some of the farmers feel that the subject has almost become taboo, “We talk very little about climate. We already know how it is—and that there is nothing we can do.”
1. What does the author imply at the beginning?| A．The origin of coffee is at risk. |
| B．Coffee consumers like reading newspaper. |
| C．The origin of coffee is visited by consumers. |
| D．Coffee consumers do care about the weather very much. |
| A．They become victims of extreme weather. |
| B．Those in Mexico suffer the greatest loss. |
| C．Some of them take measures to cut the losses. |
| D．They try to meet the market demand for coffee. |
| A．Its market share is low. |
| B．It can only be planted in Etiopia. |
| C．It has disease-causing genes. |
| D．It has high demands for environment. |
| A．easily understood. | B．rarely mentioned. |
| C．hardly avoided. | D．heatedly discussed. |
6 . Plants don’t have ears or a central nervous system, but new research out of the University of Missouri has demonstrated that they might still have the ability to “hear”. More specifically, plants have been shown to exhibit an immune (免疫) response to the mere sound of a hungry insect.
For the study, researchers played the sound of a caterpillar chewing to a group of plants, which caused slight vibrations (振动) on the plants’ leaves. The plants were able to recognize these vibration patterns as danger, and responded by mounting the appropriate immune response. In other words, it appears that plants can “hear” themselves being chewed on.
Researchers assume that plants achieve this remarkable ability thanks to proteins that respond to pressure found within their cell membranes. Vibrations cause pressure changes within the cell, which can change the behavior of the proteins; however, additional study will be required to confirm or deny this theory.
Once researchers identify the exact mechanisms at play in this process, it could lead to advances in crop protection. Farmers could potentially learn to use sound to cause a plant’s natural chemical defenses against insect threats, rather than turning to poisonous chemicals.
“We can imagine applications of this where plants could be treated with sound or genetically engineered to respond to certain sounds that would be useful for agriculture,” said study author Heidi Appel.
The study adds to the growing list of ways that plants have been shown to sense their environments. They are not the boring organisms that many people assume they are. For instance, some plants are able to communicate with each other and signal upcoming danger to their neighbors by releasing chemicals into the air. Plants can respond to light (think about sunflowers) and temperature. Some can even respond to touch, such as the Venus flytrap (捕蝇草), which snaps shut when an insect stimulates its hairs.
1. Why did researchers carry out the study?| A．To find out if plants can react to sounds. |
| B．To learn how plants recognize dangers. |
| C．To discover if plants can shake their leaves. |
| D．To see how plants improve immune systems. |
| A．To remove insects. | B．To protect crops. |
| C．To treat plant diseases. | D．To produce chemicals. |
| A．There are more plants than we know. |
| B．Plants are more active than we think. |
| C．Plants fit in well with their environments. |
| D．Lots of secrets about plants remain unclear. |
| A．Can plants “talk” with each other? |
| B．How do plants make use of sounds? |
| C．Can plants “hear” themselves being eaten? |
| D．How do plants defend themselves against attacks? |
