The scientists have now proven that  strigolactones, as hormones, are also crucial for the branching of plants. The discovery will soon be published in Nature and is of great importance for innovations in agriculture. Examples include the development of cut flowers or tomato plants with more or fewer branches. These crops are of major economic and social importance worldwide.

The growth and development of plants is largely controlled by plant hormones. Plants produce these chemicals themselves, thus controlling the growth and development of roots and stems, for example. A number of plant hormones, such as auxins, giberellins and cytokinins, were discovered by scientists decades ago. Now a new group of hormones has been found: The so-called strigolactones.

Previous research by institutes including Wageningen UR has shown that strigolactones plays a major part in the interaction between plants and their environment. As plants cannot move, they commonly use their own chemicals to control the environment as best as they can.

Strigolactones are of major importance to the interaction between plants and symbiotic fungi, for example. These fungi live in a symbiotic relationship with plants, lthat is mutually beneficial. They transport minerals from the soil to the plant, while the plant gives the fungi sugars ‘in return’.

Unfortunately, the strigolactones have also been “hijacked” by harmful organisms: They help seeds of parasitic plants to germinate when plant roots are in the vicinity. The seedlings of the parasite attach to the root of the plant and use the plant’s nutrients for their own growth and reproduction. Unlike the symbiotic fungi, however, they do not give anything in return. On the contrary, the parasitism often causes the host plant to die, eventually.

The international research team consisting of French, Australian and Dutch scientists, coordinated in France, found mutants of pea that were branching without restraint. It turned out that these pea plants were not capable of producing strigolactones. When the plants were administered strigolactones, the unrestrained branching stopped. The same effect occurred in an entirely different plant, thale cress. The mutant plants also caused a significant lower germination of the parasitic plant seeds and induced less interaction with symbiotic fungi.

The scientists also showed that a specific ‘receptor reaction’ for the strigolactones occurs in plants, a phenomenon that is characteristic for plant hormones. Although some previously discovered plants with unrestrained branching turned out to be producing strigolactones themselves, their receptor connection was disturbed: Strigolactones administered from the outside could not stop the uncontrolled branching.

It has also been shown that the plants are capable of transporting strigolactones internally and that the chemicals work at very low concentrations, two other typical characteristics of plant hormones.

It is expected that this new knowledge will be applied in agriculture and horticulture, for example in breeding and the development of branching regulators.

این هم دومین مقاله به زبان انگلیسی که در مورد بیماری آتشک که از مهمترین بیماریهای باغی هستش توضیح میده..

?What is Fire blight

Fire blight is a destructive bacterial disease of apple and pear, recognized by a severe blighting of blossoms, shoots, limbs and fruit. It also affects several ornamentals in the same family such as hawthorn, mountain ash, cotoneaster, quince and firethorn. Outbreaks of fire blight occur periodically in British Columbia pear orchards. Fire blight has also been an increasing problem in high density apple plantings of newer, more susceptible varieties.

Shoot blight on young Fuji apple. Note shepherd's crook and browning of leaves at end of shoot.

:Symptoms

Fire blight symptoms may appear on the blossoms, shoots, branches, trunk and rootstock. Blighted blossoms appear wilted, shriveled and brown. Young fruitlets are also very susceptible and appear water soaked and slightly off-colour soon after infection. Fruitlets quickly turn brown to black and eventually

آنچه به اینجا پیوند دارد... بیماری وبا کشاورزی دانشگاه صنعتی اصفهان جدول طبقه بندی زیست شناسی ساختمان سلول پروکاریوت تمایز سلولی آنتی بیوتیک رده بندی باکتریها نظرات دانشمندان غربی درباره مکمل بودن علم و دین داروسازی میکروب شناسی صنعتی انواع باکتری خاک گیاه شناسی میکروب شناسی مواد غذایی اصطلاحات رایج در زیست شناسی روشهای انتقال و انتشار ویروسها فیزیولوژی باکتریها ایمنی شناسی گروههای عمده باکتریها باکتری اثرات محیط بر باکتریها ویروس شناسی اکولوژی عمومی ایمنی در برابر انگلها منشا میکرو ارگانیسمها سم شناسی طبقه بندی ویروسها معایب و مزایای باکتریها سل رشد و تکثیر باکتریها شکل باکتری و اندازه آن میکروارگانیسمهای هوا انواع عفونت عفونت و عوامل آن بیماری و عوامل آن بیماریهای عفونی اقسام مسمومیت جعبه ابزار ویروس شناسی بیوتکنولوژی بیماری کزاز سم شناسی صنعتی جهش ژنی در باکتریها زیست شناسی

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