Agriculture Reference
In-Depth Information
of its production on respiration, changes which occur during
development and the constraints which ATP production may
place on carbon partitioning into different end products, are
important.
Cereal grain development can be divided into two main
stages, grain development and grain fi lling. The fi rst stage,
grain enlargement, involves early, rapid division of the zygote
and triploid nucleus. Cell division is followed by the infl ux
of water, which drives cell extension. This stage occurs at
approximately 3-20 day post-anthesis. During the second stage
(grain fi lling), cell division slows and then ceases and storage
products are accumulated, beginning at around 10 days after
anthesis until maturity, when the endosperm serves its function
as a carbohydrate store.
Analysis suggests that 148 distinct proteins in addition
to the highly abundant globulin and glutelin seed storage
proteins. Identifi ed proteins include those involved in RNA
processing, translation, protein modifi cation, cell signaling, and
metabolism, as well as a number of hypothetical proteins.
Micro RNAs (mi RNAs) are upstream gene regulators of
plant development and hormone homeostasis through their
directed cleavage or translational repression of the target
mRNAs, which may play crucial roles in rice grain fi lling and
determining the fi nal grain weight and yield.
Grain fi lling is divided into three stages viz. milk grain
stage, dough grain stage and mature grain stage. In the milk
grain stage, the grain has began to fi ll with a milky material.
The grain starts to fi ll with a white, milky liquid, which can be
squeezed out by pressing the grain between the fi ngers. The
panicle looks green and starts to bend. Senescence at the base
of the tillers is progressing. The fl ag leaves and the two lower
