Biliminsanlar\u0131 200 y\u0131ldan uzun s\u00fcredir besin sistemimizin temelini olu\u015fturan ve bug\u00fcn g\u00f6rd\u00fc\u011f\u00fcm\u00fcz hayvan \u00e7e\u015fitlili\u011finin b\u00fcy\u00fck b\u00f6l\u00fcm\u00fc i\u00e7in yak\u0131t g\u00f6revi g\u00f6ren \u00e7i\u00e7ekli bitkilerin inan\u0131lmaz \u00e7e\u015fitlili\u011fi ve D\u00fcnya\u2019n\u0131n d\u00f6rt bir yan\u0131ndaki ekosistemlerde bask\u0131n bitki grubu haline gelebilme ba\u015far\u0131lar\u0131 \u00fczerine fikir y\u00fcr\u00fct\u00fcyordu. Charles Darwin\u2019in \u201cberbat s\u0131r\u201d ifadeleriyle nitelendirdi\u011fi kadim problem \u00e7\u00f6z\u00fclm\u00fc\u015f olabilir.<\/p>\n
San Francisco Devlet \u00dcniversitesi ve Yale \u00dcniversitesi\u2019nden biliminsanlar\u0131, 11 Ocak\u2019ta PLOS Biyoloji Dergisi<\/em>\u2019nde konuyla ilgili eri\u015fime a\u00e7\u0131k bir makale yay\u0131nlad\u0131. Son 30 y\u0131ll\u0131k s\u00fcre\u00e7te ara\u015ft\u0131rmac\u0131lar \u00e7i\u00e7ekli bitkilerin e\u015fi benzeri olmayan bir fotosentez h\u0131z\u0131na sahip oldu\u011funu g\u00f6stermi\u015fti. Bu durum \u00e7i\u00e7ekli bitkilerin daha h\u0131zl\u0131 b\u00fcy\u00fcmesine ve ekosistemleri 100 milyonlarca y\u0131l domine eden e\u011freltiotu ve kozalakl\u0131 bitkilere kar\u015f\u0131 \u00fcst\u00fcn gelmesine olanak tan\u0131d\u0131. \u00c7i\u00e7ekli bitkilerin metabolik ba\u015far\u0131lar\u0131n\u0131n s\u0131rr\u0131, daha h\u0131zl\u0131 su ta\u015f\u0131n\u0131m\u0131 ve CO2<\/sub> al\u0131m\u0131na olanak tan\u0131yan \u00f6zelle\u015fmi\u015f yapraklar\u0131. Fakat \u00e7i\u00e7ekli bitkiler nas\u0131l oldu da bu y\u00fcksek h\u0131zl\u0131 ta\u015f\u0131n\u0131m ve fotosentez kapasitesine sahip yapraklar\u0131 \u00fcretebildi?<\/p>\n Yeni ara\u015ft\u0131rma bunun i\u00e7in bir mekanizma \u00f6neriyor. Bitkilerden elde edilen veri literat\u00fcr\u00fcn\u00fc tarayan ara\u015ft\u0131rmac\u0131lar, bu anatomik yeniliklerin bitkilerin genom boyutuyla do\u011frudan ili\u015fkili oldu\u011funu ortaya att\u0131. Her bir h\u00fccre bitki genomunun bir kopyas\u0131n\u0131 ta\u015f\u0131d\u0131\u011f\u0131ndan, daha k\u00fc\u00e7\u00fck genomlar kendilerini ta\u015f\u0131yan h\u00fccrelerin daha k\u00fc\u00e7\u00fck olmas\u0131na ve bu sayede belirli bir hacme daha fazla h\u00fccrenin (mesela fotosentetik metabolizma ve su-besin ta\u015f\u0131n\u0131m\u0131 i\u00e7in \u00f6zelle\u015fmi\u015f h\u00fccreler) s\u0131\u011fabilmesine olanak tan\u0131yor. Dahas\u0131 her bir h\u00fccrenin boyutunun s\u0131k\u0131\u015ft\u0131r\u0131lmas\u0131yla su ve g\u0131da da\u011f\u0131t\u0131m\u0131 \u00e7ok daha verimli bir \u015fekilde ger\u00e7ekle\u015ftirilebiliyor.<\/p>\n Y\u00fczlerce t\u00fcr \u00fczerinde yap\u0131lan kar\u015f\u0131la\u015ft\u0131rmalar sonucunda, ara\u015ft\u0131rmac\u0131lar genom boyutundaki k\u00fc\u00e7\u00fclmenin 140 milyon y\u0131l \u00f6nce ba\u015flad\u0131\u011f\u0131n\u0131 ve bunun ilk \u00e7i\u00e7ekli bitkilerin yery\u00fcz\u00fcnde yay\u0131ld\u0131\u011f\u0131 zamanla \u00e7ak\u0131\u015ft\u0131\u011f\u0131n\u0131 buldu.<\/p>\n Ara\u015ft\u0131rma b\u00fcy\u00fck bir soruyu yan\u0131tlasa da, ba\u015fka sorulara da kap\u0131 aral\u0131yor. Mesela neden \u00e7i\u00e7ekli bitkiler di\u011fer bitki gruplar\u0131na g\u00f6re genom boyutlar\u0131n\u0131 daha fazla s\u0131k\u0131\u015ft\u0131rma kabiliyetine sahipti? Genom yap\u0131s\u0131ndaki ve paketlemesindeki hangi yenilikten faydaland\u0131lar? E\u011freltiotlar\u0131 ve kozalakl\u0131 bitkiler b\u00fcy\u00fck genomlar\u0131 ve h\u00fccrelerine ra\u011fmen yok olmaktan nas\u0131l kurtuldu?<\/p>\n","protected":false},"excerpt":{"rendered":" Biliminsanlar\u0131 200 y\u0131ldan uzun s\u00fcredir besin sistemimizin temelini olu\u015fturan ve bug\u00fcn g\u00f6rd\u00fc\u011f\u00fcm\u00fcz hayvan \u00e7e\u015fitlili\u011finin b\u00fcy\u00fck b\u00f6l\u00fcm\u00fc i\u00e7in yak\u0131t g\u00f6revi g\u00f6ren \u00e7i\u00e7ekli bitkilerin inan\u0131lmaz \u00e7e\u015fitlili\u011fi ve D\u00fcnya\u2019n\u0131n d\u00f6rt bir yan\u0131ndaki ekosistemlerde bask\u0131n bitki grubu haline gelebilme ba\u015far\u0131lar\u0131 \u00fczerine fikir y\u00fcr\u00fct\u00fcyordu. Charles Darwin\u2019in \u201cberbat s\u0131r\u201d ifadeleriyle nitelendirdi\u011fi kadim problem \u00e7\u00f6z\u00fclm\u00fc\u015f olabilir. San Francisco Devlet \u00dcniversitesi ve Yale […]<\/p>\n","protected":false},"author":677,"featured_media":20169,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[2148,19,21,217],"tags":[2409,200,773,1185],"class_list":["post-20168","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-168-sayi","category-bilim-gundemi","category-biyoloji","category-cevre-bilimleri","tag-cicekli-bitkiler","tag-evrim","tag-genom","tag-yeryuzu"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/20168","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/users\/677"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=20168"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/20168\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/20169"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=20168"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=20168"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=20168"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}