Editing Plant cell (section)

==Characteristics of plant cells==

* Plant cells have [[cell wall]]s composed of [[cellulose]], [[hemicellulose]]s, and [[pectin]] and constructed outside the [[cell membrane]]. Their composition contrasts with the cell walls of [[fungus|fungi]], which are made of [[chitin]], of [[bacteria]], which are made of [[peptidoglycan]] and of [[archaea]], which are made of [[pseudopeptidoglycan]]. In many cases [[lignin]] or [[suberin]] are secreted by the [[protoplast]] as secondary wall layers inside the primary cell wall. [[Cutin]] is secreted outside the primary cell wall and into the outer layers of the secondary cell wall of the epidermal cells of leaves, stems and other above-ground organs to form the [[plant cuticle]]. Cell walls perform many essential functions. They provide shape to form the tissue and organs of the plant, and play an important role in intercellular communication and plant-microbe interactions.<ref name=Keegstra>{{cite journal| last=Keegstra |first=K |date=2010 |title=Plant cell walls |journal=Plant Physiology |volume=154 |issue=2 |pages=483–486 |doi=10.1104/pp.110.161240 |pmc=2949028 |pmid=20921169}}</ref> The cell wall is flexible during growth and has small pores called plasmodesmata that allow the exchange of nutrients and [[Plant hormone|hormones]] between cells.<ref>{{Cite book |last1=Lew |first1=Kristi |url=https://books.google.com/books?id=ttyPEAAAQBAJ&pg=PA12 |title=Plant Cells, Third Edition |last2=Fitzpatrick |first2=Brad |date=2021-08-01 |publisher=Infobase Holdings, Inc |isbn=978-1-64693-728-8 |language=en}}</ref>
* Many types of plant cells contain a large central [[vacuole]], a water-filled volume enclosed by a membrane known as the [[tonoplast]]<ref name=JRaven>{{Cite journal |first=JA |last=Raven |date=1997 |title=The vacuole: a cost-benefit analysis |journal=Advances in Botanical Research |volume=25 |pages=59–86 |doi=10.1016/S0065-2296(08)60148-2 |isbn=9780120059256 }}</ref> that maintains the cell's [[turgor]], controls movement of [[molecules]] between the [[cytosol]] and [[plant sap|sap]], stores useful material such as [[phosphorus]] and [[nitrogen]]<ref>{{cite journal |last=Raven |first=J.A. |date=1987 |title=The role of vacuoles |volume=106 |issue=3 |pages=357–422 | doi=10.1111/j.1469-8137.1987.tb00149.x |journal=New Phytologist|doi-access= |bibcode=1987NewPh.106..357R }}</ref> and digests waste [[protein]]s and [[organelle]]s.
* Specialized cell-to-cell communication pathways known as [[plasmodesmata]],<ref name=Oparka>{{cite journal |last=Oparka |first=KJ |date=1993 |title=Signalling via plasmodesmata-the neglected pathway |journal=Seminars in Cell Biology |volume=4 |issue=2 |pages=131–138 | doi=10.1006/scel.1993.1016|pmid=8318697 }}</ref> occur in the form of pores in the primary cell wall through which the [[plasmalemma]] and [[endoplasmic reticulum]]<ref name=Hepler>{{cite journal |last=Hepler |first=PK |date=1982 |title=Endoplasmic reticulum in the formation of the cell plate and plasmodesmata |journal=Protoplasma |volume=111 |issue=2 |pages=121–133 |doi=10.1007/BF01282070 |s2cid=8650433 }}</ref> of adjacent cells are continuous.
* Plant cells contain [[plastid]]s, the most notable being [[chloroplast]]s, which contain the green-colored pigment [[chlorophyll]] that converts the energy of sunlight into chemical energy that the plant uses to make its own food from water and carbon dioxide in the process known as [[photosynthesis]].<ref>{{Cite encyclopedia|editor-first1=James Alan |editor-last1=Bassham |editor-first2=Hans |editor-last2=Lambers |date=2018 |title=Photosynthesis: importance, process, & reactions |encyclopedia=Encyclopedia Britannica |url=https://www.britannica.com/science/photosynthesis |access-date=2018-04-15|language=en }}</ref> Other types of plastids are the [[amyloplast]]s, specialized for [[starch]] storage, [[elaioplast]]s specialized for [[fat]] storage, and [[chromoplast]]s specialized for synthesis and storage of [[pigment]]s. As in [[mitochondria]], which have a genome encoding 37 genes,<ref name=Andersonetal1981>{{cite journal |last1=Anderson |first1=S |last2=Bankier |first2=AT | last3=Barrell |first3=BG |last4=de Bruijn |first4=MH |last5=Coulson |first5=AR |last6=Drouin |first6=J |last7=Eperon |first7=IC |last8=Nierlich |first8=DP |last9=Roe |first9=BA| last10=Sanger |first10=F |last11=Schreier |first11=PH |last12=Smith |first12=AJ |last13=Staden |first13=R |last14=Young |first14=IG |date=1981 |title=Sequence and organization of the human mitochondrial genome |journal=Nature |volume=290 |issue=5806 |pages=4–65 |doi=10.1038/290457a0 |pmid=7219534|bibcode=1981Natur.290..457A |s2cid=4355527 }}</ref> plastids have their own [[genome]]s of about 100–120 unique [[gene]]s<ref name=Lui>{{cite journal |first1=L |last1=Cui |first2=N |last2=Veeraraghavan |first3=A |last3=Richter |first4=K |last4=Wall |first5=RK |last5=Jansen |first6=J |last6=Leebens-Mack |first7=I |last7=Makalowska |first8=CW |last8=dePamphilis |date=2006 |title=ChloroplastDB: the chloroplast genome database |journal=Nucleic Acids Research |volume=34 |issue=90001 |pages=D692-696 |doi=10.1093/nar/gkj055 |pmid=16381961 |pmc=1347418}}</ref> and are interpreted as having arisen as [[prokaryote|prokaryotic]] [[endosymbiont]]s living in the cells of an early [[eukaryote|eukaryotic]] ancestor of the [[embryophyte|land plants]] and [[algae]].<ref name=Margulis>{{cite book |first=L |last=Margulis |author-link=Lynn Margulis |date=1970 |title=Origin of eukaryotic cells |url=https://archive.org/details/originofeukaryot0000marg |url-access=registration |publisher=Yale University Press |location=New Haven |isbn=978-0300013535 }}</ref>
* Cell division in land plants and a few groups of algae, notably the [[Charophyta|charophytes]]<ref name=Lewis2004>{{cite journal |last1=Lewis |first1=LA |last2=McCourt |first2=RM |date=2004 |title=Green algae and the origin of land plants |journal=American Journal of Botany |volume=91 |issue=10 |pages=1535–1556 |doi=10.3732/ajb.91.10.1535 |pmid=21652308|bibcode=2004AmJB...91.1535L }}</ref> and the [[Chlorophyta|chlorophyte]] order [[Trentepohliales]],<ref name=LopezBautista>{{cite journal |last1=López-Bautista |first1=JM |last2=Waters |first2=DA |last3=Chapman |first3=RL |date=2003 |title=Phragmoplastin, green algae and the evolution of cytokinesis |journal=International Journal of Systematic and Evolutionary Microbiology |volume=53 |issue=6 |pages=1715–1718 |doi=10.1099/ijs.0.02561-0 |pmid=14657098|doi-access=free }}</ref> takes place by construction of a [[phragmoplast]] as a template for building a [[cell plate]] late in [[cytokinesis]].
* The motile, free-swimming [[sperm]] of [[bryophyte]]s and [[pteridophytes]], [[cycad]]s and ''[[Ginkgo]]'' are the only cells of land plants to have [[flagella]]<ref name=Silflow>{{cite journal |last1=Silflow |first1=CD |last2=Lefebvre |first2=PA |date=2001 |title=Assembly and motility of eukaryotic cilia and flagella. Lessons from ''Chlamydomonas reinhardtii'' |journal=Plant Physiology |volume=127 |issue=4 |pages=1500–1507 |doi=10.1104/pp.010807 |pmid=11743094 |pmc=1540183}}</ref> similar to those in [[Eukaryote#Animal cell|animal cell]]s.<ref name=Manton>{{cite journal |last1=Manton |first1=I |last2=Clarke |first2=B |date=1952 |title=An electron microscope study of the spermatozoid of ''Sphagnum'' |journal=Journal of Experimental Botany |volume=3 |issue=3 |pages=265–275 |doi=10.1093/jxb/3.3.265 }}</ref><ref name=Paolillo>{{cite journal | first=DJ Jr. | last=Paolillo |date=1967 |title=On the structure of the axoneme in flagella of ''Polytrichum juniperinum'' |journal=Transactions of the American Microscopical Society |volume=86  |issue=4 |pages=428–433 |doi=10.2307/3224266|jstor=3224266 }}</ref> The [[conifers]] and [[flowering plant]]s do not have motile sperm and lack both flagella and [[centriole]]s.<ref name="raven">{{cite book |last1=Raven |first1=PH |last2=Evert |first2=RF |last3=Eichhorm |first3=SE |date=1999 |title=Biology of Plants |url=https://archive.org/details/biologyofplants00rave_0 |url-access=registration |edition= 6th |publisher= W.H. Freeman  |location=New York |isbn=9780716762843 }}</ref>