New techniques in plant chloroplast division hold hope for agriculture

January 2003 -- Ground-breaking research at the University of Leicester into the division of chloroplasts holds out hope of a safer way of genetically modifying crops, with implications for agriculture particularly in the developing world. Using three plant types - Arabidopsis, tomato and rice - Dr Simon has been working with colleagues in the University of Leicester Department of Biology and at the Laboratory of Plant Molecular Biology at the Rockefeller University in New York to examine how chloroplasts divide in plants.

Chloroplasts make plants green and are important organelles of plant cells and vital for life on earth. Chloroplasts perform numerous tasks such as photosynthesis (generation of oxygen) and the production of amino acids and fatty acids. They have their own unique, and very small, genome, and are derived from bacteria. Comparing cell division in the E. coli bacterium with the way chloroplasts divide, the research team has isolated a new component of the division machinery in Arabidopsis, AtMinE1, and they have shown that this protein represents an evolutionary conserved link between bacterial division and chloroplast division.    Dr Simon explained: "People have tried for a long time to add genes to the chloroplast genome and adapt the levels of proteins in them.   You can engineer complex pathways in chloroplasts that you can't achieve in a cell nucleus. "The main advantage is that chloroplasts are not spread by pollen, so there is no environmental hazard in plants genetically modified in this way.   In other words there wouldn't be any cross-pollination or the development of unwanted 'superweeds'.   The gene basically dies with the plant.    "The problem is that so far this has only been done in tobacco and once in the tomato plant. Our research involves genetically controlled enlarging of the chloroplasts, so that we can blast them more efficiently with DNA attached to gold particles encoding valuable proteins followed by re-manipulation of the division process."

The work was recently published in The Plant Journal, in a report entitled "The topological specificity factor AtMinE1 is essential for correct plastid division site placement in Arabidopsis", by Dr Simon and Jodi Maple of the University of Leicester Department of Biology and Nam-Hai Chua of the Laboratory of Plant Molecular Biology, the Rockefeller University, New York. The research team is also working with collaborators in the USA on putting vaccines into chloroplasts of plants so that they can be eaten.

Правила чтения химических формул

Буквы латинского алфавита, обозначающие название элементов, читаются согласно английским названиям букв алфавита.

 Знак + читается plus, and, together, with, react with.

 Знак — обозначает одну связь или единицу родства и не читается.

 Знак = читается give, form или produce.

 Знак → читается give, pass over to lead to.

 Знак ↔ читается forms and is formed from.

Цифра перед названием элемента обозначаeт число молекул.

Примеры:

 C + O₂ → CO₂

1 atom of carbon reacts with 1 two-atom molecule of oxygen and produces 1 molecule of carbon dioxide.

 2H₂ + O₂ → 2H₂O

a) Two molecules of H two plus O two give two molecules of H two O.

b) Two two-atom molecules of hydrogen react with 1 two-atom molecule of oxygen and produce two molecules of water.

 N₂ + 3H₂ ↔ 2NH₃

a) N two plus three molecules of H two form and are for­med from two molecules of NH three

b) 1 two-atom molecule of nitrogen plus three two-atom molecules of hydrogen form and are formed from two mole­cules of ammonia.

 Na₂CO₃ + CaSO₄ → Na₂SO₄ + CaCO₃

a) Na two CO three plus CaSO four form Na two SO four plus CaCO three

b) The sodium (Na) and the calcium (Ca) switch

c) The sodium combines with the sulphate radical (SO₄), form­ing sodium sulphate (Na₂SO₄) which dissolves in water.

d) The calcium сombines with the carbonate radical (CO₃), forming calcium carbonate (CaCO₃).

e) Calcium carbonate does not dissolve in water, and so settles to the bottom of the solu­tion.

Знаки + или - стоящие в левом верхнем углу, обозначают положительную и отрицательную валентность иона.

Пример: H+  a) hydrogen ion

b) univalent positive hydrogen ion

Сu ++  divalent positive cuprum ion

Al +++  trivalent positive cuprum ion

Cl -  a) negative chlorine ion

b) negative univalent chlorine ion